JPH09324172A - Water dispersion-based mold release agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water dispersion-based mold release agent capable of manifesting excellent mold releasability and nonmigrating properties. SOLUTION: This water dispersion-based mold release agent is obtained by dispersing a mold release agent composition comprising [A] a mold release agent component prepared by reacting one equiv. hydroxyl group of (a) a vinyl acetate (co)polymer having 300-5000 polymerization degree and >=50mol% saponification degree with (b) a long-chain alkyl compound, having a functional group, selected from the group consisting of isocyanate, carboxyl, an acid halide, ketene, aldehyde and epoxy groups and reactive with hydroxyl group and a 6-30C alkyl group in an amount of >=0.5 equiv. expressed in terms of the functional group and [B] a polymeric surfactant in water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dispersed release agent comprising a partially saponified vinyl acetate resin modified with a long-chain alkyl compound.

[0002]

2. Description of the Related Art Generally, adhesive tapes, adhesive labels, etc.
Until the time of use, a protective sheet is attached for the purpose of protecting the adhesive layer, and peeled off when used. Therefore, the protective sheet needs to be easily peelable from the adhesive layer, and it is not preferable that the adhesive force between the protective sheet and the adhesive layer is too strong. From this viewpoint, a release agent is usually applied to the contact surface of the protective sheet with the adhesive layer for the purpose of facilitating peeling between the protective sheet and the adhesive layer.

The role of the release agent is to protect the pressure-sensitive adhesive layer and to facilitate peeling from the pressure-sensitive adhesive, and at the time of peeling, the release layer undergoes cohesive failure and migrates to the pressure-sensitive adhesive layer. Performance that does not reduce the adhesive strength, so-called non-migrating property is required. Furthermore, this non-migratory property is required to be substantially unchanged with the passage of time and high temperature.

As the release agent, a silicone-based release agent made of polyorganosiloxane, a long-chain alkyl modified product of polyvinyl alcohol, a long-chain alkyl modified product of polyethyleneimine, etc. are generally used. Usually, it is used in the form of a solution using an organic solvent as a solvent.

However, in recent years, a solvent-free method has been promoted due to safety and environmental problems, and a hot-melt type release agent used by heating and melting a water-dispersed release agent or release agent composition containing water as a solvent. Various mold releasing agents such as a mold releasing agent, a monomer type releasing agent that cures a releasing monomer by a radical polymerization, a cationic polymerization, a polycondensation reaction and the like have been studied.

Since it is difficult to apply a hot-melt type release agent or a monomer type release agent thinly and uniformly on a substrate,
A water-dispersed release agent is strongly required and various proposals have been made. For example, JP-A-3-86778 uses an aqueous dispersion obtained by post-emulsifying a long-chain alkyl graft polymer obtained by reacting polyvinyl alcohol, polyallyl alcohol or a modified product thereof with an alkyl isocyanate. An aqueous release agent characterized by the above is disclosed. In addition, JP-A-6-73351
The publication discloses a release agent obtained by reacting polyvinyl alcohol, polyethylene imine, or the like with a long-chain alkyl isocyanate and dissolving or modifying these modified products in water together with a surfactant. .

However, in order to exhibit releasability and non-migrating property, all such water-based release agents must be heated for a long time after coating, as compared with solvent-based release agents. There is a problem. Further, the releasing property and non-migrating property thus developed are insufficient as compared with the solvent-based releasing agent, and if the composition is changed to improve these performances, the water-based releasing agent is changed. However, there are problems that the storage stability of the release agent is reduced, aggregation and sedimentation of the release agent occur, and it becomes difficult to disperse the release agent in water itself.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and after coating with a coating amount equivalent to that of a solvent-based releasing agent, without causing aggregation or sedimentation for a long period of time. It is an object of the present invention to provide a water-dispersed release agent capable of exhibiting excellent release property and non-migratory property by heating and drying for a short time.

[0009]

The water-dispersed release agent of the invention according to claim 1 of the present application (hereinafter referred to as the first invention) is acetic acid having a polymerization degree of 300 to 5000 and a saponification degree of 50 mol% or more. The vinyl (co) polymer (a) has a functional group selected from the group consisting of an isocyanate group, a carboxyl group, an acid halide group, a ketene group, an aldehyde group and an epoxy group, per 1 equivalent of a hydroxyl group, and having a functional group capable of reacting with a hydroxyl group. A release agent component [A] obtained by reacting a long-chain alkyl compound (b) having an alkyl group having 6 to 30 carbon atoms in a ratio of 0.5 equivalent or more in terms of functional group, and a polymer surface active agent A release agent composition comprising the agent [B] is dispersed in water.

The invention described in claim 2 of the present application (hereinafter referred to as “second
The water-dispersed release agent of the invention) is characterized in that wax [C] is added to the release agent composition of the first invention.

The difference between the water-dispersed release agent of the first invention and the second invention (hereinafter, both are referred to as the present invention) is that the composition of the release agent is [A] and [A]. B] and the latter consists of [A], [B], and [C].

Regarding the partially saponified vinyl acetate (co) polymer used as the component (a) of the release agent component, the vinyl acetate (co) polymer before saponification is a vinyl acetate homopolymer or a copolymer thereof. Examples thereof include copolymers with polymerizable vinyl monomers, such as vinyl acetate polymers, vinyl acetate-ethylene copolymers and vinyl acetate-acrylic acid copolymers, and at least one of them can be used. The degree of polymerization of these has to be 300 to 5000, and preferably 800 to 2500. When it is less than 300, the releasing performance of the obtained releasing agent component is deteriorated,
When it exceeds 5,000, the obtained release agent becomes difficult to disperse in water.

The degree of saponification of vinyl acetate (co) polymer is 50.
% Or more, and preferably 60% or more. When the degree of saponification is less than 50%, the amount of reactive hydroxyl groups decreases, so that the release performance of the release agent obtained using this decreases. The saponification degree means the molar ratio (%) of the number of units of the saponified vinyl acetate moiety to the total number of units of the monomers constituting the vinyl acetate (co) polymer.

The long-chain alkyl compound used as the component (b) of the release agent component is at least one reaction selected from the group consisting of isocyanate group, carbonyl group, acid halide group, ketene group, aldehyde group and epoxy group. Having a functional group and reacting with the hydroxyl group of the partially saponified vinyl acetate (co) polymer, the carbon number of the alkyl group must be 6 to 30, and preferably 8 to 28. When the number of carbon atoms in the alkyl group is less than 6, the releasing performance of the resulting release agent component becomes insufficient. On the contrary, when the number of carbon atoms in the alkyl group exceeds 30, the partially saponified vinyl acetate component (a) is used. Reactivity with (co) polymers is reduced.

Thus, the long-chain alkyl compound used as the component (b) is not particularly limited to the present invention, but those having an isocyanate group include hexyl isocyanate, octyl isocyanate, dodecyl isocyanate, octadecyl isocyanate and docosa. Nyl isocyanate and the like, those having a carboxyl group, octanoic acid, dodecanoic acid, octadecanoic acid, docosanoic acid and the like, as those having an acid halide group, octanoyl chloride, dodecanoyl chloride, octadeca Noyl chloride, docosanoyl chloride and the like, and those having a ketene group include octyl ketene dimer, dodecyl ketene dimer, octadecyl ketene dimer, docosanyl ketene dimer and the like. As those having an aldehyde group, hexyl aldehyde, octyl aldehyde, dodecyl aldehyde, octadecyl aldehyde, docosanyl aldehyde and the like, and those having an epoxy group include octyl glycidyl ether, dodecyl glycidyl ether, octadecyl glycidyl ether, Docosanyl glycidyl ether and the like can be mentioned, and at least one of these is preferably used.

The release agent component [A] is used in an amount of 1 equivalent of hydroxyl group of the partially saponified vinyl acetate (co) polymer which is the component (a).
It is necessary that the long-chain alkyl compound which is the component (b) is reacted at a ratio of 0.5 equivalent or more in terms of functional group, and preferably 0.6 equivalent or more. If it is less than 0.5 equivalent, the releasability of the obtained release agent component will be insufficient.

The method of synthesizing the releasing agent component is not a special method, and in the solvent, one long equivalent of the component (b) is added to one equivalent of the hydroxyl group of the vinyl acetate (co) polymer which is the component (a). The desired releasing agent component can be obtained by reacting the alkyl compound at a ratio of 0.5 equivalent or more in terms of functional group. The type of solvent used for synthesizing the release agent component is not particularly limited, but is preferably selected according to the type of functional group contained in the long-chain alkyl compound which is the component (b).

That is, in the case of an isocyanate group or a ketene group, an inert solvent which does not react with an isocyanate group or a ketene group such as toluene or dimethylsulfoxide is used.
The reaction is carried out by the suspension method or the dissolution method. In the case of a carboxyl group, it is preferable to use a solvent such as toluene that is used in a normal esterification reaction, and in the case of an acid halide group, it is preferable to carry out the reaction using an inert solvent that does not react with the acid halide group. During the reaction, it is more preferable to add a dehydrohalogenating agent such as pyridine.

When the functional group is an aldehyde group, it is preferable to carry out the reaction using an inert solvent that does not react with the aldehyde group, and it is more preferable to add an acid catalyst such as hydrochloric acid. Further, when the functional group is an epoxy group, it is preferable to carry out the reaction using an inert solvent that does not react with the epoxy group, and it is more preferable to add an alkali catalyst such as sodium hydroxide during this reaction.

The reaction between the component (a) and the component (b) can be traced by infrared absorption spectrum or the like, and when the hydroxyl group of the partially saponified vinyl acetate (co) polymer or the functional group of the long-chain alkyl compound disappears. Ends with.

As the polymer surfactant [B], a substance having a high molecular weight surface activity as compared with the molecular weight of conventional surfactants is used. Specifically, for example, poly (meth) acrylic acid, butyl (meth) acrylate-acrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, etc., polyalkyl (meth)
Acrylic acid homopolymers or copolymers; maleic acid copolymers such as vinyl acetate-maleic anhydride copolymers, styrene-maleic anhydride copolymers, diisobutylene-maleic acid copolymers; methyl (meth) Fumaric acid copolymers such as acrylate-fumaric acid copolymers and vinyl acetate-fumaric acid copolymers; aromatic sulfones such as naphthalenesulfonic acid formalin condensate, butylnaphthalenesulfonic acid formalin condensate, and cresolsulfonic acid formalin condensate Acid formalin condensate; polyalkylpyridinium salts such as poly-N-methylvinylpyridinium chloride (including derivatives from copolymers of vinylpyridine and vinyl monomer copolymerized therewith); polyacrylamide, polyvinylpyrrolidone, polyacryloylpyrrolidone , Polyvinyl alcohol Block polymer of polyoxyethylene and polyoxypropylene; polyethylene glycol, cellulose derivatives such as carboxymethyl cellulose; gum arabic, and polysaccharides derivatives such as arabinogalactan, and these at least one can be used.

In specific examples of the above polymer surfactant,
The polymer surfactant having a carboxyl group or a sulfone group may be an alkali salt such as sodium, potassium or ammonium.

The weight average molecular weights of the conventional ionic (cationic, anionic, amphoteric) or nonionic surfactants are less than 1000 and less than 2000, respectively, but the weight of the polymeric surfactant used in the present invention is less than that. The ionic surfactant preferably has an average molecular weight of 10 to 3,000,000, more preferably 2000 to 400,000, and the nonionic surfactant preferably has 2,000 to 3,000,000.
More preferably, it is 4000 to 400,000. If the weight average molecular weight of the polymeric surfactant is too small, the effect of stabilizing the dispersion of the release agent component in water becomes poor as in the case of the conventional surfactant. On the other hand, if it is too large, when the release agent component is dispersed in water, the viscosity becomes too high and the dispersing operation becomes difficult.

The blending amount of the polymer surfactant is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the releasing agent component,
More preferably, it is 10 to 70 parts by weight. When the amount is less than 1 part by weight, it becomes difficult to emulsify and disperse the release agent component, or the stability of the obtained water-dispersed release agent decreases. or,
If it exceeds 100 parts by weight, the release agent component tends to migrate to the adhesive layer when the obtained water-dispersed release agent is used.

The wax [C] used in the second invention is used as a release agent composition when a water-dispersed release agent is applied to a release sheet base material, dried and heated when a release sheet is produced. Since it plays a role of promoting melting and improving the film forming property of the dispersed particles of the release agent composition, it is possible to produce a release sheet having excellent release properties by heating and drying for a short time. Therefore, the wax [C] is unsuitable if the added wax softens the release agent composition and deteriorates the release performance when the produced release sheet is in stock. Therefore, it is preferable to use a thermoplastic medium-molecular-weight oligomer having a melting point of 50 ° C. or higher and having an extremely low melt viscosity at a temperature of the melting point or higher, specifically, 1 to 5000 mPas.
・ S is preferable.

[C] Wax includes natural wax and synthetic wax. Examples of natural waxes include animal waxes such as beeswax, whale wax, Chinese insect wax, shellac wax; plant waxes such as carnauba wax, oliculis wax, candelilla wax, wood wax, and cane wax; montan wax, ozokerite. , Mineral waxes such as ceresin; petroleum waxes such as paraffin wax and microcrystalline wax.

As synthetic waxes, Fischer-Tropsch wax and its derivatives, low molecular weight polyethylene and its derivatives, atactic polypropylene,
Synthetic hydrocarbon wax such as α-olefin wax, wax of montan derivative, microwax derivative, modified wax such as synthetic oxide wax; ester wax such as polyethylene glycol and sorbitol stearate; hydrogenated wax such as castol wax and opal wax Amines such as accra wax, armowax, monostearyl urea, distearyl urea, N, N'-ethylene bis stearylamide, amide waxes; halogenated hydrocarbon waxes; and at least one of them Can be used.

The content of these waxes is preferably 1 to 50 parts by weight, more preferably 3 to 40 parts by weight, based on 100 parts by weight of the release agent component. When it is less than 1 part by weight, the effect of improving the film-forming property of the release agent composition is poor, and when it exceeds 50 parts by weight, the release performance is deteriorated.

In the water-dispersed release agent of the present invention, in addition to the release agent component, the resin can be easily dispersed in water, and the wettability when the water-dispersed release agent is applied to the substrate is improved. Fatty acids, acid-modified polyolefin (co) polymers, solvents, high-boiling liquid substances, general surfactants, in order to improve, suppress foaming during coating, and increase the strength of the release film after coating. An optional additive such as a cross-linking agent may be added depending on the purpose. Hereinafter, the above-mentioned optional additives to be added to the water-dispersed release agent of the present invention other than the release agent composition will be sequentially described.

The fatty acid preferably has 10 to 30 carbon atoms, and more preferably 12 to 26 carbon atoms. When the carbon number of the fatty acid is less than 10, the polarity becomes too high, the fatty acid is separated from the release agent component, or the melting point is lowered. Decrease non-migratory property. When the number of carbon atoms exceeds 30, the polarity becomes too low, it becomes difficult to disperse in water, and the melt viscosity becomes too high,
After applying the obtained water-dispersed release agent to a substrate, heating for a long time is required in order to develop releasability and non-migratory property, which hinders the working process.

Specific examples of fatty acids include, for example, dodecanoic acid (lauric acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), octadecenoic acid (oleic acid), icosanoic acid (arachidic acid), docosanoic acid. Examples thereof include saturated or unsaturated fatty acids such as (behenic acid), and at least one of them can be used.

These fatty acids are naturally salts of these fatty acids in the presence of alkali metal hydroxides such as sodium hydroxide and barium hydroxide, and alkaline earth hydroxides. The fatty acid in 1 shall include a fatty acid salt.

The amount of the fatty acid added is not particularly limited, but is 1 to 50 parts by weight with respect to 100 parts by weight of the release agent component obtained by reacting the components (a) and (b). It is preferable that the amount is 3 to 40 parts by weight. When the amount of the fatty acid added is less than 1 part by weight, it becomes difficult to uniformly and stably emulsify and disperse the release agent component in water during the production of the water-dispersed release agent, and the resulting water is obtained. In order to apply the dispersion type release agent to the base material and develop the releasing property and the non-migrating property, long-time heating is required.
It interferes with the work process. Conversely, the amount of fatty acid added is 50
When the amount is more than parts by weight, the non-migration property of the resulting water-dispersed release agent is reduced.

The acid-modified polyolefin (co) polymer has a function of uniformly and stably emulsifying and dispersing the release agent component of the present invention in water, and the acid value is preferably in the range of 0.2 to 800, more preferably Is 10 to 200. Acid value is 0.
When it is less than 2, it becomes difficult to disperse itself in water, and when the acid value exceeds 800, it becomes easy to separate from the release agent component, and it is difficult to obtain a uniform and stable water-dispersed release agent. Becomes

The acid-modified polyolefin (co) polymer is not particularly limited, but includes olefins such as ethylene, propylene and butene-1 and acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinylpyrrolidone and the like. Examples thereof include copolymers with a vinyl monomer having a polar group, acrylic acid-modified polyethylene wax, chemically or physically oxidized polyethylene, polypropylene, polyolefin (co) polymers such as polybutene, and the like. One kind is preferably used.

In the copolymer of the olefin and the vinyl monomer having a polar group, the content of the polar vinyl monomer is not particularly limited, but is preferably 0.01 to 40 mol%. More preferably 0.5 to
10 mol%.

The degree of polymerization of the acid-modified polyolefin (co) polymer is not particularly limited, but is 10 to 2000.
Is preferable, and more preferably 20 to 10
00. When the degree of polymerization is less than 10, it is in a softened state even at room temperature, so that the releasing property and non-migrating property of the obtained water-dispersed release agent are deteriorated. On the other hand, when the degree of polymerization exceeds 2000, it becomes difficult to disperse it in water, and it takes a long time to apply the resulting water-dispersed release agent to the base material to develop releasability and non-migration property. Heating is required, and the work process is hindered.

The melting point and melt viscosity of the acid-modified polyolefin (co) polymer are not particularly limited, but the melting point is not lower than 40 ° C. and the melt viscosity at 140 ° C. is 1000.
It is preferably 0 Pa · s or less, and particularly, the melting point is 60 ° C. or more and the melt viscosity at 140 ° C. is 5000.
It is more preferably Pa · s or less. Melting point is 40 ° C
When the amount is less than the above, the releasing property and non-migrating property of the obtained water-dispersed release agent are insufficient, and when the melt viscosity at 140 ° C. exceeds 10,000 Pa · s, it becomes difficult to disperse in water.

The amount of the acid-modified polyolefin (co) polymer added is not particularly limited, but is based on 100 parts by weight of the release agent component obtained by reacting the components (a) and (b). , 1 to 50 parts by weight, and more preferably 3 to 40 parts by weight. When the addition amount is less than 1 part by weight, it becomes difficult to uniformly and stably emulsify and disperse the release agent component in water during production of the water-dispersion type release agent. It takes a long time to apply releasability and non-migration property to the base material, which causes trouble in the working process. On the other hand, if the addition amount exceeds 50 parts by weight, the non-migratory property of the obtained water-dispersed release agent decreases.

As the solvent, a hydrocarbon solvent such as octane and an aromatic solvent such as toluene are used, and the amount thereof is preferably 10 parts by weight or less based on 100 parts by weight of the entire solution of the water-based release agent. . If it exceeds 10 parts by weight, it is not preferable for safety and hygiene.

The high boiling point liquid substance has a boiling point of 100 under normal pressure.
It is preferably at least 0 ° C, has a viscosity at room temperature of 100 Pa · s or less, and does not significantly impair the adhesive performance of the adhesive even when transferred to the adhesive layer of an adhesive processed product such as an adhesive tape. If the boiling point is less than 100 ° C., the resulting water-dispersed release agent tends to volatilize during coating and drying, so exhaust,
A recovery device is required, which leads to an increase in manufacturing cost. On the other hand, if the viscosity exceeds 100 Pa · s, the fluidity becomes low, and the effect of improving the wettability and film-forming property of the water-dispersed release agent becomes poor.

The high-boiling-point liquid substance is not particularly limited, but examples thereof include naphthenic oils, lanolin, oligomers of olefins, process oils such as vegetable oils, animal oils and mineral oils, liquid rosins and turpentine oils. Examples thereof include tackifier resins, plasticizers such as polybutene and diisodecyl phthalate, and at least one of them can be used.

Examples of general surfactants include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants, and at least one of them can be used.

Examples of nonionic surfactants include:
Polyoxyethylene alkyl phenyl ether; ether type such as polyoxyethylene alkyl ether; glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester sugar ester type; polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, etc. ester type , Fatty acid alkanolamide type.

Examples of anionic surfactants include:
Carboxylic acid type such as fatty acid monocarboxylic acid salt and N-acryloylglutamate, alkylbenzene sulfonate,
Examples include naphthalene sulfonate-formaldehyde condensate, sulfonic acid type such as sulfosuccinic acid dialkyl ester, sulfuric acid ester type such as alkyl sulfate salt, and phosphoric acid ester type such as alkyl phosphate salt.

As the cationic surfactant, for example,
Amine salt type such as alkyl amine salt, alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt,
Examples thereof include quaternary ammonium salt type such as alkyldimethylbenzyl ammonium salt.

As the amphoteric surfactant, for example, N,
Examples thereof include carboxybetaine type such as N-dimethyl-N-alkylaminoacetic acid betaine and glycine type such as 2-alkyl-1-hydroxyethyl-1-carboxymethylimidazolinium betaine.

The cross-linking agent is not particularly limited as long as it can react with the release agent component by heat, light or the like to cross-link when a water-dispersed release agent is applied to a substrate to form a film. Although not limited, for example, polyvalent isocyanate compounds, blocked polyvalent isocyanate compounds, polyvalent epoxy compounds, polyvalent acryloyl compounds, polyvalent methylol compounds, polyvalent ionic metals, polyvalent aziridine compounds and the like, these, At least one of can be used.

In the water-dispersed release agent of the present invention,
A release agent composition comprising a release agent component [A] obtained by reacting a component (a) with a component (b) and a polymer surfactant [B], or a wax [C] in the composition. And at least one optional additive selected from the group consisting of fatty acids, acid-modified polyolefin (co) polymers, solvents, high-boiling-point liquid substances, general surfactants, crosslinking agents, etc. is added. Then, these are made into a release agent composition and dispersed in water. The average particle size (volume average particle size) of the release agent composition dispersed in water, including these optional additive components, is 1
It is preferable that the particles are dispersed so that the particle size is not more than μm.

When the average particle diameter of the release agent composition dispersed in water exceeds 1 μm, it is necessary for the release sheet to have a reduced releasability and non-migration property, or to exhibit sufficient releasability. The coating amount increases or the storage stability of the water-dispersed release agent is impaired. This fact means that when the average particle size becomes large, the water-dispersed particles become unstable and become more likely to aggregate in the process of coating and heating / drying on the substrate, and the surface of the release sheet substrate It is also presumed from the fact that it is observed that the coating rate of the release agent composition of No. 2 becomes smaller and a base material surface not coated with the release agent is generated.

The average particle size (volume average particle size) referred to here is "new experimental chemistry course 18 (interface and colloid)".
p. 368 to 407 and can be measured by methods such as electron microscopy, laser diffraction light scattering method, and dynamic light scattering method, the average particle diameter in the present invention is a volume-based average particle diameter, and A laser diffraction / scattering type particle size distribution analyzer (for example, trade name “9220FRA”,
It means the particle size at which the cumulative value of the frequencies from the lower limit or the upper limit in the particle size distribution (particle size distribution) curve measured using MICROTRAC is 50%.

The method for producing the water-dispersed release agent of the present invention is not particularly limited. For example, the release agent composition is heated and melted in advance, heated water is added thereto, and pressure is applied. Using a mixer such as a kneader, colloid mill, or high-speed stirring shaft, the mixture is subjected to high shear to uniformly emulsify and disperse until the average particle diameter becomes 1 μm or less, and then cooled so that the dispersed particles do not fuse and aggregate. , A method of obtaining a desired water-dispersed release agent (high-pressure emulsification method), or a release agent composition is previously dissolved in an organic solvent, and the solution and water are subjected to high shear using a high-speed emulsifier. And an average particle diameter of 1 μm or less are uniformly emulsified and dispersed, and then an organic solvent is removed to obtain a desired water-dispersed release agent (solvent dissolution method). It is suitable for use, but above all, it does not require the removal of organic solvents and the process is simple. The emulsification method is more preferably adopted.

The specific procedure of the high-pressure emulsification method is, for example, a release agent component, a polymeric surfactant, and a wax, if necessary, mixed with optional additives, heated and melted, and then the melt. Add heated water to, add high shear to disperse,
First, a W / O type emulsion (an emulsion in which water is dispersed in oil) is prepared, and hot water is added to the emulsion to invert the phase of the water-dispersed release agent ( O / W emulsion). After that, the dispersed particles are cooled so that they do not aggregate. The heating and melting temperature is not particularly limited, but is preferably 60 ° C. or higher, and more preferably,
Pressurize to 120 ° C or higher. Further, the release agent composition is not heated and melted in advance, but is put into water all at once, and uniformly emulsified and dispersed under pressure at a temperature of about 120 ° C. under high shear until the average particle diameter becomes 1 μm or less. After this, a method of cooling to obtain a desired water-dispersed release agent may be adopted.

In either the high pressure emulsification method or the solvent dissolution method, the mixing ratio of the release agent component and water is
The release agent composition 5 to 50 is not particularly limited.
It is preferable that the content is wt% and the water content is 95 to 50 wt%. When the content of the release agent composition is less than 5% by weight, the shearing effect at the time of emulsification and dispersion is diminished and the production efficiency is lowered. On the contrary, the content of the release agent composition exceeds 50% by weight. If so, the viscosity becomes too high, which makes uniform emulsion dispersion difficult. Further, the water-dispersed release agent obtained through the emulsification / dispersion step may be diluted with water as needed as long as the storage stability is not impaired.

The water-dispersed release agent of the present invention is used for producing an ordinary release sheet, and the release sheet is prepared by coating the substrate with the water-dispersed release agent, heating and drying the release sheet. It is manufactured by providing a release layer on the base material. Examples of the base material used for the release sheet include plastic films such as polyethylene, polypropylene, polyester and cellophane, papers such as high quality paper, kraft paper, crepe paper, glassine paper, impregnated paper and plastic coated paper. Examples of the material include cloths such as sealed papers, non-woven fabrics, cloths, and the like, and at least one of these may be laminated and used.
Incidentally, the base material, in order to improve the adhesion between the water-dispersed release agent composition and the base material, at least one surface thereof, corona treatment,
Pretreatment such as plasma treatment or primer treatment is preferably performed.

Examples of the method of applying the water-dispersed release agent to the substrate include a method of using a general coating device such as a roll coater, a gravure coater, a Mayer bar coater, and a lip coater. A release sheet is obtained by evaporating the water of the water-dispersed release agent through a drying furnace. The thickness of the water-dispersed release agent applied to the substrate is
It is preferable that one side of the substrate has a solid content of 1 μm or less. If it exceeds 1 μm, it takes a long time to heat and dry, resulting in an increase in cost and non-migration property of the obtained release layer.

Usually, the water-dispersed release agent remains on the base material in the state of the particles of the release agent composition as they are when the water is simply evaporated to leave the base material and the release agent composition. Poor adhesion with
In many cases, the release agent property and non-migration property are not sufficient. For that reason,
After coating and drying the water-dispersion release agent, it is preferable to further apply pressure and heat to the water-dispersion release agent coating layer of the base material. It is necessary to melt and smooth the agent composition to enhance the adhesiveness with the base material.

As the method of pressurizing / heating, for example,
A method in which a base material coated with a water-dispersion release agent and dried is sandwiched between high-temperature presses to press and heat it (press method), and a method of pressurizing and heating it between heating rolls (roll method) And the like, and any of them is preferably adopted, but the roll method, which is excellent in productivity, is more preferably adopted.

The heating temperature during pressurization / heating is not particularly limited, but is preferably higher than the softening point of the release agent component, usually 60 ° C. or higher, more preferably 80 ° C. or higher. is there. The pressure at the time of pressurization / heating is not particularly limited and depends on the pressure resistance of the base material, but is usually preferably 0.1 to 500 kg / cm ² . During pressurization / heating, the adhesiveness between the roll and the release agent composition needs to be lower than the adhesiveness between the release agent component and the release sheet base material. It is inconvenient that the agent component is transferred to the roll. Therefore, as the material of the heating roll, an elastic material that is heat-resistant and releasable and uniformly pressurizes the release agent component is required. All are preferably used.

In order to improve productivity, it is preferable that the pressure / heating roll is connected to a coating / drying facility, and the peripheral speed of the roll is synchronized with the line speed. It is determined by the time required for the heating process and the line speed.

(Function) The water-dispersed release agent of the first invention is a release agent composition prepared by mixing a long-chain alkyl compound-modified partially saponified vinyl acetate (co) polymer with a polymer surfactant in water. It is dispersed. The difference from the conventional water-dispersed release agent is that the molecular weight of the surfactant contained in the release agent composition is
In the conventional release agent composition, the ionic type is less than 1000,
In the nonionic type, the amount is less than 2000, while in the water-dispersed release agent of the present invention, it is 1000 to 300 in the ionic type.
It is a nonionic type and has a value of 20 to 3 million.

The water-dispersed release agent obtained by using the polymer surfactant is such that the polymer surfactant is a protective colloid on the emulsified particles of the release agent composition finely dispersed in water. In addition, it is presumed that the surface of the emulsified dispersed particles is further covered to stabilize the dispersed particles. Therefore, when applied to a release sheet base material, particles of the release agent composition do not aggregate,
It is possible to form a release agent layer evenly on the substrate without locally agglomerating the release agent composition in the process of applying in a uniformly filled / aligned state and heating / drying. ,
As a result, the release agent layer, which is a thin film and has a large surface area, can easily separate dispersed particles from water in the drying step, efficiently evaporates water, and is excellent in heating and drying in a short time. It is presumed that releasability and non-transferability can be expressed.

The wax [C] used in the second invention is used as a release agent composition when a water-dispersed release agent is applied to a release sheet base material, dried and heated when a release sheet is produced. Since it plays a role of promoting melting and improving the film forming property of the dispersed particles of the release agent composition, it is possible to produce a release sheet having excellent release properties by heating and drying for a short time.

[0064]

BEST MODE FOR CARRYING OUT THE INVENTION In order to explain the present invention in more detail, examples, comparative examples and reference examples will be given.

Synthesis of various releasing agent components 1) Synthesis of releasing agent component R1 In a reaction vessel equipped with a stirrer, a cooler, a dropping funnel, and a thermometer, polyvinyl alcohol (polymerization degree 1100, saponification degree 9
8 mol%) 10 g are dispersed in 50 g of dehydrated xylene, and 67 g of octadecyl isocyanate at the reflux temperature.
And 0.01 g of a catalyst (dibutyltin dilaurate) were added and reacted. As the reaction progressed, the polyvinyl alcohol powder disappeared, but after completely disappearing, the reaction was continued for 2 hours. Then, it cooled to 40 degreeC and the reaction solution was poured into 1000 g of methanol, and the white precipitate was obtained. This was washed with methanol, then with hexane, and dried to obtain a release agent component R1.

2) Combination of release agent components R2 and CR1 to CR4
The release agent components R2, CR1, CR2, CR were prepared in the same manner as in the synthesis of R1 in 1) above except that the following raw materials were used.
3, CR4 was synthesized. R2: Polyvinyl alcohol (polymerization degree 1500, saponification degree 69 mol%) 10 g Octadecyl isocyanate 57 g CR1: Polyvinyl alcohol (polymerization degree 200, saponification degree 98 mol%) 10 g Octadecyl isocyanate 67 g CR2: Polyvinyl alcohol (polymerization degree 1100, saponification degree 40) Mol%) 10 g octadecyl isocyanate 30 g CR3: polyvinyl alcohol (polymerization degree 1100, saponification degree 98 mol%) 10 g ethyl isocyanate 16 g CR4: polyvinyl alcohol (polymerization degree 1100, saponification degree 98 mol%) 10 g octadecyl isocyanate 30 g

3) Synthesis of release agent component R3 In a reaction vessel equipped with a stirrer, a cooler, a dropping funnel and a thermometer, an ethylene-vinyl alcohol copolymer (polymerization degree: 15
00, saponification degree 69 mol% = vinyl alcohol portion ratio, ethylene copolymerization ratio 30 mol%) 10 g were dispersed in 300 g of dehydrated pyridine. At 80 ° C., 80 g of octadecylyl chloride was added and reacted with the ethylene-vinyl alcohol copolymer. With the progress of the reaction, the powder of the ethylene-vinyl alcohol copolymer disappeared, but after completely disappearing, the reaction was further continued for 2 hours. Then, cool to 40 ° C., and add 1500 g of the reaction solution.
Was poured into methanol to obtain a white precipitate. This was washed with methanol, then with hexane, and dried to obtain a release agent component R3.

Examples and comparative examples according to the first invention will be described below.

Example 1 1) Preparation of Water-Dispersion Release Agent A water-dispersion release agent was prepared with the following composition. Release agent component R1 135 g S1; high molecular surfactant; sodium salt of carboxylic acid-containing vinyl polymer M _W 4000 49 g SA1; general surfactant; sorbitan monostearate M _W 430 1 g high boiling solvent; kerosene 15 g water 800 g

Method for Producing Water-Dispersion-Based Release Agent A release agent component R was added to a high-pressure emulsifier under pressure and heating.
1. Polymer release agent S1 and a releasing agent component consisting of kerosene as a high boiling point solvent are charged, and the mixture is heated at 95 ° C. for 10 minutes to 500.
Stir at rpm to obtain a molten mixture. Next, 800 g of water in which a general surfactant SA1 (1 g) is dissolved is heated to 100 ° C. under pressure, and first, 50 g of water therein is
While stirring at 1000 rpm in the high-pressure emulsifier, the mixture was slowly added dropwise to disperse water in the release agent composition to prepare a W / O type emulsion. Then, the remaining 750 g of water at 100 ° C. was stirred at a stirring speed of 5000
The mixture was added dropwise under rpm to carry out phase inversion emulsification into an O / W type emulsion, and then gradually cooled to prepare an aqueous dispersion type release agent. As shown in Table 1, the obtained water-dispersed release agent had an average particle size of 0.39 μm and was stable for a long time without sedimentation or aggregation.

2) Preparation of release sheet Polyethylene was extrusion-laminated to a thickness of 20 μm on Klupack kraft paper having a basis weight of 75 g / m ² , and corona was applied so that the surface tension of the polyethylene surface was 44 dyn / cm. The discharge treatment was performed to obtain a tape-based sealing paper. Next, a diluting water containing 0.04% by weight of sodium dioctylsulfosuccinate having an effect of wettability with a base material was prepared, and the water-dispersed release agent obtained in 1) had a solid content of 2%.
Dilute with water so that the amount of the coating solution becomes 10% by weight, and use a # 6 Meyer bar coater on the polyethylene side of the sealing paper so that the coating amount after drying is 0.2 g / m ² (the undried coating amount). Of 10 g / m ² ) and dried and film-formed in a drying oven at a temperature of 120 ° C. for 30 seconds to obtain a release sheet. An adhesive tape (manufactured by Sekisui Chemical Co., Ltd .; craft tape # 504) was attached to the obtained release sheet, and various performances were measured by the methods described below. As a result, as shown in Table 1,
As compared with the comparative example shown in Table 2, a release sheet having good release performance was obtained.

Examples 2 to 7 Various release agent components, the following polymeric surfactants, general surfactants, high boiling point solvents, and water were used in the formulations shown in Table 1 to prepare Examples 1 and 2. Similarly, a water-dispersed release agent and a release sheet were prepared. As shown in Table 1, as compared with Comparative Examples shown in Table 2, the stability of the water-dispersed release agent is excellent, and a release sheet having excellent release performance can be obtained by heating and drying for a short time. It was

Polymeric surfactant: S2; sodium salt of β-naphthalenesulfonic acid formalin condensate, M _W 8000 S3; ethyl cellulose, ethyl group substitution degree: 0.6 degree of polymerization 100, M _W 15,000 general surfactant : SA2; stearyltrimethylammonium chloride, M _W 334 SA3; polyoxyethylene nonylphenyl ether,
_MW 1650

[0074]

[Table 1]

Comparative Examples 1 to 3 As shown in Table 2, the same procedure as in Example 1 was carried out except that general surfactants: SA1, SA2 and SA3 were used without using the polymer surfactant. A water-dispersed release agent was prepared. A release sheet was prepared in the same manner as in Example 1 except that the water-dispersed release agent obtained above was used to double the drying time before aggregation occurred. As a result, as shown in Table 2, the stability of the water-dispersed release agent was poor and the performance of the release sheet was poor.

Comparative Example 4 A release sheet was produced in the same manner as in Comparative Example 1 except that the water-dispersed release agent of Comparative Example 3 was used and the drying time was the same as in Example 1. As a result, the release performance was further deteriorated, and it was found that when the water-dispersed release agents of Comparative Examples 1 to 4 were used, a good release sheet could not be obtained by heating and drying for a short time.

Comparative Example 5 As shown in Table 2, a release sheet was prepared in the same manner as in Comparative Example 1 except that the water-dispersed release agent of Comparative Example 3 was used to increase the average coating amount. It was made. As a result, the releasing performance was improved, but was not sufficient as compared with the examples.

Comparative Example 6 As shown in Table 2, an aqueous dispersion type release agent was prepared in the same manner as in Example 1 except that a general surfactant was used without using a polymer surfactant. Was produced. As a result, agglomeration occurred immediately after the release agent composition was dispersed in water.

Comparative Examples 7 to 11 As shown in Table 2, the same procedure as in Example 1 was carried out except that the composition of various releasing agent components, general surfactants, polymer surfactants and the like was changed. A water-dispersed release agent was prepared. A release sheet was prepared in the same manner as in Example 1 except that the water-dispersed release agent obtained above was used to increase the drying time before aggregation occurred. As a result, as shown in Table 2, the stability of the water-dispersed release agent was poor and the performance of the release agent sheet was also poor.

[0080]

[Table 2]

Reference Examples 1 to 3 The release agent components (R1 to R3) were diluted with the organic solvent toluene so that the solid content was 2% by weight, and polyethylene for sealing paper was prepared in the same manner as in Example 1. On the surface, with a # 6 Meyer bar coater, the solid content was 0.2 g / m ² (the solution was 1
0 g / m ² ) was applied. In the same drying oven as in Example 1, 12
It was dried at 0 ° C. for 30 seconds to obtain a release sheet. Adhesive tape (craft tape # 50 manufactured by Sekisui Chemical Co., Ltd.)
4) was attached and various evaluations were made by the methods described below.
As a result, as shown in Table 3, a release sheet having a release performance as good as that of the example was obtained. From the above,
The water-dispersed release agent compositions of Examples have the same level of performance as solvent-based release agents, and are free from the environmental problems of organic solvents.

[0082]

[Table 3]

Next, examples and comparative examples according to the second invention will be described.

Example 8 1) Preparation of Water-Dispersion Release Agent A water-dispersion release agent was prepared with the following composition. Release agent component R1 135 g S1; polymeric surfactant; sodium salt of carboxylic acid-containing vinyl polymer M _W 4000 49 g SA1; general surfactant; sorbitan monostearate M _W 430 1 g W1; wax; paraffin wax, Melting point: 75 ° C. 15 g High boiling point solvent; Kerosene 15 g Water 775 g

Method for producing water-dispersed release agent A release agent component R is added to a high-pressure emulsifying machine under pressure and heat.
1, a polymeric surfactant S1, a wax W1, and a release agent component consisting of a high boiling point solvent are charged, and the mixture is heated at 95 ° C. for 10 minutes for 5 minutes.
Stir at 00 rpm to obtain a molten mixture. Next, 775 g of water in which a general surfactant SA1 (1 g) is dissolved
Is heated to 100 ° C. under pressure, and first, 50 g
The above water was slowly added dropwise to the high-pressure emulsifier while stirring at 1000 rpm to disperse the water in the release agent composition to prepare a W / O type emulsion. Thereafter, the remaining 725 g of 100 ° C. water was stirred at a stirring speed of 500
The mixture was added dropwise at 0 rpm to carry out phase inversion emulsification into an O / W type emulsion, and then gradually cooled to prepare an aqueous dispersion type release agent. As shown in Table 4, the obtained water-dispersed release agent had an average particle diameter of 0.39 μm and was stable for a long time without sedimentation or aggregation.

2) Production of release sheet A release sheet was produced in the same manner as in Example 1 using the obtained water-dispersed release agent, and an adhesive tape (manufactured by Sekisui Chemical Co .; craft tape) was prepared. # 504) was pasted and various performances were measured by the method described below. As shown in Table 4,
A release sheet having good release performance was obtained as compared with the comparative example.

Examples 9 to 16 Various release agent components, polymer surfactants, stearic acid, modified polyolefins, general surfactants, waxes, high boiling point solvents, and water were used in the formulations shown in Table 4. Then, in the same manner as in Example 8, an aqueous dispersion type release agent and a release sheet were produced. As shown in Table 4, as compared with the comparative example in Table 5, the stability of the water-dispersed release agent is excellent, and heating / drying in a short time
A release sheet having excellent release performance was obtained.

Acid-modified polyolefin; ethylene-acrylic acid copolymer, degree of polymerization 250, acrylic acid content 4 mol%, acid value 80 wax W2; montan wax, melting point 80 ° C. W3; monostearyl urea, melting point 100 ° C.

[0089]

[Table 4]

Comparative Examples 12 to 13 As shown in Table 5, except that no wax was used,
A water-dispersed release agent and a release sheet were prepared in the same manner as in Examples 8 and 9. As a result, as shown in Table 5, the release performance of the release sheet was not sufficient.

Comparative Example 14 A release sheet was prepared using the water-dispersed release agent of Comparative Example 12 with a longer drying time than that of Comparative Example 12. As a result, the release performance was satisfactory, but the drying time was long.

Comparative Examples 15-18 As shown in Table 5, water-dispersed release agents were prepared in the same manner as in Examples 13-16 except that no wax was used.
A release sheet was produced in the same manner as in Example 8. As a result, as shown in Table 5, the release sheet was unsatisfactory.

Comparative Example 19 As shown in Table 5, an aqueous dispersion type release agent was obtained in the same manner as in Example 8 except that the polymer surfactant and the wax were not used. A release sheet was produced in the same manner as in Example 8 except that the water-dispersed release agent was used to increase the drying time before aggregation occurred. As a result, as shown in Table 5, the stability of the water-dispersed release agent was poor, and the release performance of the release sheet was also poor.

Comparative Example 20 The procedure of Comparative Example 19 was repeated, except that the water-dispersed release agent of Comparative Example 19 was used and the drying time was the same as that of Example 8.
A release sheet was produced. As a result, the release performance was further deteriorated, and the water-dispersed release agent of Comparative Example 19 could not obtain good release performance when the drying time was short.

[0095]

[Table 5]

Comparative Example 21 As shown in Table 6, a release sheet was produced in the same manner as in Comparative Example 19 except that the water-dispersed release agent of Comparative Example 19 was used and the average coating amount was increased. As a result, the releasing performance was improved, but it was insufficient as compared with the examples.

Comparative Example 22 As shown in Table 6, an aqueous dispersion type release agent was obtained in the same manner as in Example 8 except that the polymer surfactant was not used.
A release sheet was produced in the same manner as in Example 8 except that the water-dispersed release agent was used to increase the drying time before aggregation occurred. As a result, as shown in Table 6, the stability of the water-dispersed release agent was poor and the release performance of the release sheet was also poor.

Comparative Examples 23 to 29 As shown in Table 6, the procedure of Example 8 was repeated except that the composition of the releasing component, the polymer surfactant and the like was changed.
A water-dispersed release agent was obtained. A release sheet was produced in the same manner as in Example 8 except that the drying time was extended by using the water-dispersed release agent before aggregation occurred (except for Comparative Example 28). As a result, as shown in Table 6, the stability of the water-dispersed release agent was poor and the release performance of the release sheet was also poor.

[0099]

[Table 6]

Method for measuring performance of water-dispersed release agent and release sheet
Various evaluation items shown in Method Tables 1 to 6 were performed by the following methods. Storage stability A water-dispersed release agent was diluted with ion-exchanged water so that the solid content was 1% by weight, and allowed to stand for 72 hours in an atmosphere of 23 ° C, and then checked for aggregation, sedimentation, layer separation, etc. It was visually observed and the storage stability was evaluated according to the following criteria. In addition, a water-diluted solution of a water-dispersed release agent is filtered through a 200-mesh stainless filter, the filtration residue is dried, and then the weight is measured,
The weight ratio (% by weight) to the total solid content of the diluted solution before standing at 23 ° C. for 72 hours was determined. [Judgment Criteria] ∙ No aggregation, sedimentation, or layer separation was observed, and storage stability was good ..... Aggregation, sedimentation, layer separation was observed, and storage stability was insufficient. Occurred, and an aqueous dispersion type release agent could not be obtained.

Average particle diameter (volume average particle diameter) Laser diffraction / scattering particle size distribution meter (trade name "9220FR
A ”, manufactured by MICROTRAC) was used to dilute the water-dispersed release agent to a predetermined concentration, and the measurement was performed.

Spreading force According to JIS Z-0237 "Adhesive tape / adhesive sheet test method", an adhesive tape (trade name "craft tape # 504" cut into a strip of 25 mm in width on the release surface of the release sheet. , Manufactured by Sekisui Chemical Co., Ltd.) is attached with a pressure roller to prepare a test piece, and the test piece is prepared in an atmosphere of 23 ° C. and 65% RH.
After standing for 4 hours, a "180 degree peeling test" was performed in the same atmosphere using a high-speed peeling tester at a peeling speed of 10 m / min to determine a developing force (g / 25 mm). The lower the spreading force, the better the releasability of the release sheet.

A test piece prepared in the same manner as in the case of the residual adhesive force developing force was
After standing in an atmosphere of 65 ° C. and 65% RH for 24 hours, the adhesive tape was peeled off from the release sheet. Then JIS Z
According to -02237, the peeled pressure-sensitive adhesive tape is attached to a stainless plate with a pressure roller and left in an atmosphere of 23 ° C. and 65% RH for 24 hours, and then 300 mm using a high-speed peeling tester in the same atmosphere. At a peeling rate of
Peel strength P (g / 25m
m) was measured. Separately, using an adhesive tape not attached to the release sheet, the adhesive tape was attached to the stainless plate in the same manner, and the peel strength was measured under the same conditions.
(G / 25 mm). The ratio [(P / 2010) × 100] of both peel strengths was calculated, and the residual adhesive strength (%) was obtained. The closer the residual adhesive strength is to 100%, the smaller the transfer amount of the release agent component to the pressure-sensitive adhesive layer is.

The water-dispersed release agent of the present invention can be applied to a release base material such as paper or plastic, or a tape support, which has conventionally been applied with a solvent-based or UV-curable release agent. Needless to say, it can also be applied to a release base material that is not resistant to solvents and monomers. In particular, for the back surface release treatment of an adhesive tape having polycarbonate or polystyrene as a support, direct coating with the water-dispersed release agent of the present invention is possible, which is highly useful.

[0105]

As described above, since the water-dispersed release agent of the present invention is constituted as described above, it has excellent storage stability and can be dried and heated for a short time after being applied to a substrate. , Excellent release properties can be exhibited, and the property that the release agent component does not migrate to the pressure-sensitive adhesive layer can be exhibited.

Claims (2)

[Claims] 1. A degree of polymerization of 300 to 5,000, a degree of saponification of 5
React with a hydroxyl group selected from the group consisting of an isocyanate group, a carboxyl group, an acid halide group, a ketene group, an aldehyde group, and an epoxy group, per 1 equivalent of a hydroxyl group of 0 mol% or more of vinyl acetate (co) polymer (a). Has a functional group that
A release agent component [A] obtained by reacting a long-chain alkyl compound (b) having an alkyl group having 6 to 30 carbon atoms at a ratio of 0.5 equivalent or more in terms of functional group, and a polymeric surfactant. A release agent composition comprising [B] and a release agent composition, wherein the release agent composition is dispersed in water. 2. The water-dispersed release agent according to claim 1, wherein wax [C] is added to the release agent composition.