JPH068392B2 - Method of forming moisture-permeable film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for forming a moisture-permeable film on a substrate such as various structures, wood, cloth and paper.

[Prior Art] It has been well known that a nonionic surfactant is used as an emulsifier in emulsion polymerization. As a nonionic surfactant for emulsion polymerization, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether, polyoxyalkylene fatty acid ester or the like is used.

However, when emulsion polymerization is carried out using these surfactants, the resulting film has poor moisture permeability, so when it is used as a paint or adhesive, adhesion failure, swelling of the coating film, peeling, or structure There is a drawback that dew condensation is likely to occur on the inner wall, and there is a problem that the industrial application range is extremely limited. However, when emulsion polymerization is carried out using a large amount of nonionic surfactant beyond the common sense of those skilled in the art, the moisture permeability of the obtained emulsion film is considerably improved, while other physical properties such as water resistance are obtained. However, there is a problem in that the practical value thereof is extremely reduced.

[Problems to be solved by the invention]

As a result of intensive studies to solve the above problems found in conventional emulsifiers for emulsion polymerization, the present inventors have found that vinyl monomers described above are nonionic surfactants for conventional emulsion polymerization and certain polyalkylene glycols. When an emulsion obtained by emulsion polymerization was formed into a film in the presence of a mixture in a specific range with a class of compounds, the film was found to have extremely excellent moisture permeability, and the method of the present invention was reached.

[Means for solving problems]

That is, the method of forming a moisture-permeable film of the present invention is a method in which a vinyl monomer is used as a polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether or polyoxyalkylene fatty acid ester in an amount of 60 to 85% by weight and an average molecular weight of 800 to 6,000. 20 to 7 solids obtained by emulsion polymerization in the presence of 1 to 8 wt% of an emulsifier consisting of 40 to 15 wt% of alkylene glycol.
It is characterized in that an aqueous dispersion containing 0% by weight of an emulsion as a main component is applied onto a substrate to form a film having a thickness of 10 to 5,000 μ.

[Action]

It is not clear why the emulsion-polymerized resin composition in the method of the present invention exhibits excellent moisture permeability when formed into a film. However, it is considered that the combination of the emulsifiers specified in the present invention affects the physical properties of the produced resin to give a film having a microstructure suitable for moisture permeability.

Hereinafter, the configuration of the present invention will be described in detail.

The polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether and polyoxyalkylene fatty acid ester (hereinafter referred to as nonionic emulsifier) used in the present invention have an alkyl group having 4 to 2 carbon atoms.
0, preferably in the range of 8 to 15, the alkylene oxide is selected from ethylene oxide, propylene oxide, and butylene oxide, and the average number of added moles is 3 to 80.
It is preferably 20 to 50 mol, and ethylene oxide is suitable for 50% by weight or more of the alkylene oxide. When emulsion polymerization is carried out using an emulsifier outside these specific ranges, aggregates and the like are produced in both cases, and an emulsion in a preferable state cannot be obtained, or even if an emulsion in a good state is obtained. However, this film does not exhibit favorable moisture permeability, and the intended purpose may not be achieved in some cases.

The polyalkylene glycol is selected from polyethylene glycol alone or a mixture of polyethylene glycol and polypropylene glycol and / or polybutylene glycol. When a mixture is used, 50% by weight or more of it is preferably polyethylene glycol. . Further, the average molecular weight of these polyalkylene glycols is 800 to 6,000, and more preferably 2,000 to 4,000. When emulsion polymerization is performed using a polyalkylene glycol other than these specific ranges, any of them is preferable. If you can not get the emulsion of the state,
Alternatively, even if obtained, the film is not preferable because it does not exhibit favorable moisture permeability and does not serve the intended purpose.

The mixing ratio by weight of the nonionic emulsifier to the polyalkylene glycol is in the range of 85:15 to 60:40, more preferably 80:20 to 70:30. The polyalkylene glycol in these mixtures may be either a product that is mixed as a by-product during the production of the nonionic emulsifier, or a product that is intentionally added and mixed after the production. The mixing ratio is 85:
When the mixing amount of the polyalkylene glycol is less than 15, an emulsion in a good state can be obtained even when emulsion polymerization is performed using this as an emulsifier, but the obtained film has favorable moisture permeability for its application. Is not indicated, which is inconvenient. Also, if the mixing amount of polyalkylene glycol is more than 60:40, it is not possible to obtain an emulsion in good condition such as a large amount of coagulum even if emulsion polymerization is carried out using this as an emulsifier. However, the coating is inferior in physical properties such as water resistance and is not preferable in application.

When emulsion polymerization is performed using the emulsifier of the present invention, the amount used in the emulsion is 1 to 8% by weight, preferably 2 to 6% by weight. When the amount used is less than 1% by weight, the obtained film does not show favorable moisture permeability. On the contrary, when the amount used exceeds 8% by weight and is more than that, a good emulsion can be obtained. Or, even if it is obtained, the water resistance of the formed film is extremely poor, and both are inconvenient.

The emulsifier used in the present invention may be only a mixture of a nonionic emulsifier and a polyalkylene glycol, but other nonionic surfactants, anionic surfactants, water-soluble polymers within a range not impairing the effects of the present invention. Etc. may be used together. Examples of other nonionic surfactants include ethylene oxide propylene oxide block copolymers and sorbitan derivatives. Examples of anionic surfactants include long-chain alkyl sulfates, long-chain alkylbenzene sulfonates, polyoxyethylene alkyl sulphates and the like. Examples of water-soluble polymers include polyvinyl alcohol and hydroxyethyl cellulose. When these compounds are used in combination, 0.02 to 5 parts by weight is suitable for 1 part by weight of the nonionic emulsifier in the emulsifier of the present invention.

The polymerized resin which is the main component of the emulsion-polymerized resin composition of the present invention may be a polymer of an emulsion-polymerizable vinyl-based monomer, and is not particularly limited, among which an acrylic acid ester resin, an acrylic acid ester. Copolymer resins, styrene copolymer resins, vinyl acetate resins, vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins and the like are preferable from the physical properties of the formed film. Specific examples of vinyl monomers used in these resins include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylic acid such as methyl methacrylate, or esters of methacrylic acid; bromide. Vinyl halides such as vinyl, vinyl chloride and vinylidene chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl aromatic monomers such as styrene and vinyl toluene; monoolefins or conjugated diolefins such as ethylene and butadiene; Α, β unsaturated amides such as acrylonitrile; acrylic acid,
Α, β unsaturated carboxylic acids such as methacrylic acid, itaconic acid, maleic acid, fumaric acid; vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane,
γ-methacryloxypropyltrimethoxysilane, γ-
There are vinylalkoxysilanes such as glycidoxypropyltrimethoxysilane and γ-glycidoxypropylmethyldiethoxysilane, and glycidoxyalkoxysilanes, which may be used alone or in combination of two or more.

In the emulsion polymerization of the present invention, the polymerization initiator used includes, for example, hydrogen peroxide solution, potassium persulfate, ammonium persulfate, etc., and if necessary, sodium hydrogen sulfite, ascorbic acid, tartaric acid, sodium thiosulfate, etc. You may use together the reducing agent of.

As a method for producing the emulsion-polymerized resin composition of the present invention, conventionally known emulsification means can be applied as the emulsion-polymerization means itself. For example, the concentration of the vinyl monomer is 20 to 70% by weight, and the emulsifier is 1.4 to 20 parts by weight per 100 parts by weight of the vinyl monomer.

The emulsion used in the present invention has a solid content in the range of 20 to 70% by weight, preferably 30 to 60% by weight, and the viscosity is not particularly limited.

Furthermore, if necessary, a pH adjuster, a polymerization degree adjustor, and other auxiliary additives may be used. As an auxiliary additive,
There are various antifoaming agents, preservatives, thickeners, film-forming aids, solvents, film-forming aids, water repellents, etc., which are appropriately added and used according to their applications. In particular, addition and use of various water-repellent agents such as fluorine-based, silicone-based, polyethylene wax-based, paraffin wax-based, etc., in addition to the moisture permeability of the film for the purpose of the present invention, the water repellency and water resistance of the film preferable for its application. Is effective as a means to improve.

The aqueous dispersion thus obtained is applied onto a substrate to form a film. The applicable base material may be any base material that requires moisture permeability, for example, mortar, slate, gypsum board, calcium silicate board, hard board, lightweight cellular concrete, asbestos cement board, wood wool cement board, Building materials such as pulp cement board and dolomite plaster,
Examples include paper, fibers, textiles, leather, wood and other industrial substrates. As a coating means, brush coating, roller coating,
A coating method generally used in the relevant industry such as bar coater coating, spray coating, shower coating, and roll coating is adopted.

The moisture-permeable film formed by the method of the present invention has a thickness of 10 to 50.
The thickness is 00 μ, and it can be widely used from a flat coating film of 20 to 30 μ to a multilayer elastic coating film of thick film and a thick film tile-shaped coating material for lines.

〔Example〕

Hereinafter, the method of the present invention will be described in more detail with reference to specific examples.

In addition, the moisture permeability of the film of various emulsions in the specific example was measured by applying the emulsion to Kent paper with a bar coater (# 50).
It was dried at 00 ° C. for 15 minutes and measured as a test body in accordance with JIS Z 0208 moisture-proof packaging material moisture permeability test-method A.

For weather resistance, an emulsion was used to prepare a sample with a film thickness of 300 μ on the mortar surface using an air spray type spray gun.
This sample was irradiated with a sunshine carbon arc lamp type weather resistance tester (WEL-SUN-HC type gas tester) for 300 hours, and appearance changes such as blisters, peeling, cracks, peeling and discoloration were observed.

Example 1 108.8 parts by weight of water was added to a reaction vessel equipped with a thermometer, a stir bar, a reflux condenser, and a dropping funnel, the temperature was raised to 70 ° C., and the system was replaced with nitrogen gas. On the other hand, a mixture of 33.75 parts by weight of polyethylene oxide lauryl ether having 40 moles of ethylene oxide added and 11.25 parts by weight of polyethylene glycol having an average molecular weight of 3,000 was dissolved in 365.5 parts by weight of water, and 95.3 parts by weight of styrene and 2- Ethylhexyl acrylate 434.1 parts by weight, methacrylic acid 10.3
539.7 parts by weight of the mixed monomer of 53 parts by weight is added, stirred, well emulsified, and added to a dropping funnel. Next, 46.0 parts by weight of this emulsion was added to the reactor, and 10.6 parts by weight of a 10% by weight aqueous solution of ammonium persulfate and 10.6 parts by weight of a 10% by weight aqueous solution of sodium hydrogen sulfite were respectively added as polymerization initiators. Uniform dropping was carried out for 3 hours from separate dropping funnels. After dripping, aging reaction is performed at 70 ° C for 1 hour,
A desired emulsion was obtained.

Example 2 In the same manner as in Example 1, the number of moles of ethylene oxide added was 30 instead of polyoxyethylene lauryl ether.
Emulsion polymerization was carried out using the polyoxyethylene nonylphenyl ether of 1 to obtain the desired emulsion.

Example 3 51.4 parts by weight of methyl methacrylate as a monomer, n
-Emulsion polymerization was performed in the same manner as in Example 1 except that 478.0 parts by weight of butyl acrylate was used to obtain a desired emulsion.

Example 4 51.4 parts by weight of methyl methacrylate as a monomer, n
-Emulsion polymerization was performed in the same manner as in Example 2 except that 478.0 parts by weight of butyl acrylate was used to obtain a desired emulsion.

Example 5 Example 1 except that 360.0 parts by weight of styrene and 169.4 parts by weight of 2-ethylhexyl acrylate were used as monomers.
Emulsion polymerization was carried out in the same manner as above to obtain the desired emulsion.

Example 6 336.7 parts by weight of methyl methacrylate as a monomer, n
-Emulsion polymerization was performed in the same manner as in Example 3 except that 192.7 parts by weight of butyl acrylate was used to obtain the desired emulsion.

Comparative Example 1 42.75 parts by weight of polyethylene glycol lauryl ether having an addition mole number of ethylene oxide of 40 and an average molecular weight of 3,000
Emulsion polymerization was carried out in the same manner as in Example 1 except that 2.25 parts by weight of polyethylene glycol was used to obtain an emulsion.

Comparative Example 2 42.75 parts by weight of polyoxyethylene nonylphenyl ether having 30 moles of ethylene oxide added and an average molecular weight of 3,0
Emulsion polymerization was carried out in the same manner as in Example 1 except that 2.25 parts by weight of polyethylene glycol of 00 was used to obtain an emulsion.

Comparative Example 3 42.75 parts by weight of polyethylene glycol lauryl ether having an addition mole number of ethylene oxide of 40 and an average molecular weight of 3,000
Emulsion polymerization was carried out in the same manner as in Example 3 except that a mixture of 2.25 parts by weight of polyethylene glycol was used to obtain an emulsion.

Comparative Example 4 Emulsion polymerization was carried out in the same manner as in Example 4 except that a mixture of 42.75 parts by weight of polyoxyethylene oxide nonylphenyl ether having 30 moles of ethylene oxide added and 2.25 parts by weight of polyethylene glycol having an average molecular weight of 3,000 was used. , An emulsion was obtained.

Comparative Example 5 3.75 parts by weight of polyethylene oxide lauryl ether having an addition mole number of 40 of polyethylene oxide and an average molecular weight of 3,
000 of polyethylene glycol was used in a mixture with 1.25 parts by weight of polyethylene glycol, and 102.5 parts by weight of styrene and 466.9 parts by weight of 2-ethylhexyl acrylate were used as monomers to carry out emulsion polymerization in the same manner as in Example 1 to obtain a desired emulsion. It was

Comparative Example 6 81.0 parts by weight of polyethylene oxide lauryl ether having a mole number of polyethylene oxide added of 40 and an average molecular weight of 3,
Emulsion polymerization was carried out in the same manner as in Example 1 except that a mixture of 000 and 27.0 parts by weight of polyethylene glycol was used as a monomer, and 84.0 parts by weight of styrene and 382.4 parts by weight of 2-ethylhexyl acrylate were used. Although an emulsion can be obtained, the polymerization stability is poor and there are many lumps, which is a problem in practical use.

The results of the above Examples and Comparative Examples are summarized in Table 1.

Example 7 A stainless steel autoclave having an internal volume of 1.5 and equipped with a stirrer, 474.3 parts by weight of water, and a polyethylene oxide lauryl ether having 40 moles of ethylene oxide added.
A mixture of 33.75 parts by weight and 11.25 parts by weight of polyethylene glycol having an average molecular weight of 3,000 is filled and the stirring speed is 250 rpm.
Nitrogen substitution was carried out while stirring at 2, then ethylene substitution was carried out, and the subsequent ethylene pressure was set to 50 kg / cm ² , and the autoclave was heated to 70 ° C.

Next, 458.7 parts by weight of vinyl acetate and 10.6 parts by weight of a 10% by weight aqueous ammonium persulfate solution and 10.6 parts by weight of a 10% by weight aqueous sodium hydrogen sulfite solution were uniformly added separately over 3 hours. Then, the temperature is raised to 85 ° C. and aging is carried out for 1 hour, and the ethylene: vinyl acetate copolymerization ratio (weight ratio) is 1
A copolymer resin emulsion of 5:85 was obtained.

Example 8 Emulsion polymerization was performed in the same manner as in Example 1 except that 539.7 parts by weight of vinyl acetate was used as a monomer and methyl methacrylate was removed, to obtain a desired emulsion.

Example 9 Emulsion polymerization was carried out in the same manner as in Example 1 except that 78.4 parts by weight of vinyl acetate and 461.3 parts by weight of n-butyl acrylate were used as monomers, and methyl methacrylate was removed to obtain a desired emulsion.

Comparative Example 7 Emulsion polymerization was carried out in the same manner as in Example 7 except that a mixture of 42.75 parts by weight of polyethylene oxide lauryl ether having 40 moles of added ethylene oxide and 2.25 parts by weight of polyethylene glycol having an average molecular weight of 3,000 was used to form an emulsion. Obtained.

Comparative Example 8 Emulsion polymerization was carried out in the same manner as in Example 8 except that a mixture of 42.75 parts by weight of polyethylene oxide lauryl ether having 40 moles of ethylene oxide added and 2.25 parts by weight of polyethylene glycol having an average molecular weight of 3,000 was used to form an emulsion. Obtained.

Comparative Example 9 Emulsion polymerization was carried out in the same manner as in Example 9 except that a mixture of 42.75 parts by weight of polyethylene oxide lauryl ether having 40 moles of ethylene oxide added and 2.25 parts by weight of polyethylene glycol having an average molecular weight of 3,000 was used. Obtained.

The above results are summarized in Table 2.

Example 10 Emulsion polymerization was carried out in the same manner as in Example 1 except that 90.3 parts by weight of styrene, 428.5 parts by weight of 2-ethylhexyl acrylate, and 10.6 parts by weight of vinyltris (2-methoxyethoxy) silane were used as monomers. A desired emulsion was obtained.

[Effects of the Invention] The method of the present invention provides a remarkably excellent moisture-permeable film as compared with a film formed from a conventional emulsion-polymerized resin composition, and therefore has a very high practical value as a method for protecting and coating various substrates.

Claims (1)

[Claims] 1. A vinyl-based monomer comprising 60 to 85% by weight of polyoxyalkylene alkyl ether, polyoxyalkylene alkylphenyl ether or polyoxyalkylene fatty acid ester and 40 to 15% by weight of polyalkylene glycol having an average molecular weight of 800 to 6,000. In the presence of 1 to 8% by weight of an emulsifier consisting of and, an aqueous dispersion mainly composed of an emulsion having a solid content of 20 to 70% by weight, which is obtained by emulsion polymerization, is applied onto a substrate to form a thick film. 10-5000μ
A method for forming a moisture-permeable film, characterized in that the film is formed on.