JP6301591B2 - Vinyl acetate resin emulsion and method for producing the same - Google Patents

Description

  The present invention relates to a vinyl acetate resin emulsion and a method for producing the same.

  In recent years, in the field of using a coating agent or an adhesive using a vinyl acetate resin emulsion, the precision and density when coating these are becoming very important factors due to market needs. Control of coating amount and coating thickness, and improvement in coating properties such as smoothness and surface properties of the coated surface are required. With respect to coating properties, it is important to control the rheological properties of the vinyl acetate resin emulsion, and it is known that the particle size and particle size distribution of the vinyl acetate resin emulsion have a great influence on the rheological properties.

  As a method for producing a vinyl acetate resin emulsion, a predetermined amount of monomer is added to an aqueous solution of a surfactant such as an emulsifier or a protective colloid such as polyvinyl alcohol, and a polymerization initiator is added thereto to react. A seed polymerization method is known in addition to a general emulsion polymerization method in which particles are generated in a system by starting, and then a monomer is further added successively to grow the particles. The seed polymerization method is a polymerization method in which emulsion particles (seed) already produced by ordinary emulsion polymerization are previously present in a polymerization tank prior to the reaction, and a polymer is newly generated while further adding monomers thereto. . It is known as an emulsion polymerization technique that can produce particles larger than emulsion particles added initially by performing emulsion polymerization again in the emulsion particles added initially or on the surface layer. Such a seed polymerization method has already been widely used in various fields including acrylic resin emulsions. A method of performing seed polymerization using an ethylene vinyl acetate resin emulsion as a seed is also known (Patent Documents 1 to 5).

  In Patent Document 1, an ethylene vinyl acetate copolymer resin emulsion having an ethylene content of 10 to 40 wt% is used, and after adding polyvinyl alcohol having a saponification degree of 80 to 99 mol% and a polymerization degree of 200 to 3500, acetic acid is added. A seed polymerization resin is prepared by adding a monomer containing a vinyl monomer and emulsion polymerization by adding a vinyl acetate monomer and an ethylene vinyl acetate resin emulsion so that the solid content ratio is 10 to 200/100. A method for obtaining an emulsion is described. Patent Document 2 uses an ethylene vinyl acetate copolymer resin emulsion having an ethylene content of 10 to 55 wt%, and after adding polyvinyl alcohol having a saponification degree of 90 to 98 mol% and a number average molecular weight of 400 to 2000, Seed polymerization by adding a monomer containing vinyl acetate monomer so that the solid content ratio of the monomer containing vinyl acetate and the ethylene vinyl acetate resin emulsion is 100/5 to 40, followed by emulsion polymerization. A method for obtaining a resin emulsion is described. Patent Document 3 uses an ethylene vinyl acetate copolymer resin emulsion having an ethylene content of 10 to 30 wt%, and 5 to 15 parts by weight of polyvinyl alcohol having a saponification degree of 80 to 89 mol% and a polymerization degree of 300 to 2300. After the addition, the monomer containing the vinyl acetate monomer is added so that the ratio of the solid content of the vinyl acetate-containing monomer to the ethylene vinyl acetate resin emulsion is 100 / 8-30, and emulsion polymerization is performed. A method for obtaining a seed polymerized resin emulsion is described. In Patent Document 4, an ethylene vinyl acetate copolymer resin emulsion having an ethylene content of 15 to 35 wt% is used, and polyvinyl alcohol in an amount of 9 to 20 wt% is added to the solid content of the vinyl acetate resin emulsion. After that, seed polymerization is carried out by adding vinyl acetate in a proportion that the content of ethylene vinyl acetate copolymer resin is 50% by weight or less as a solid content with respect to the total of ethylene vinyl acetate copolymer resin and vinyl acetate. A woodworking adhesive for adhering wood to wood containing a vinyl acetate resin emulsion that does not contain a plasticizer is obtained. In Patent Document 5, when polyvinyl alcohol is used as a protective colloid and core-shell emulsion polymerization is performed using a vinyl acetate monomer and an acrylic acid monomer, emulsion polymerization of the core portion is performed using the vinyl acetate monomer. A method for producing a vinyl acetate resin emulsion is described in which emulsion polymerization of a shell portion is performed using a vinyl acetate monomer and an acrylic acid monomer.

Further, Non-Patent Document 1 describes the film formation mechanism of a vinyl acetate resin seed polymerization emulsion using an ethylene vinyl acetate copolymer resin emulsion as a seed. By forming as particles, the film-forming property at low temperature can be controlled well, and further, the shear stress and shear rate in the shear rate region of 10 ² s ⁻¹ are obtained from the results of rheological considerations on these vinyl acetate resin emulsions. It is disclosed that if the storage elastic modulus G ′ in the region of 10 ⁻³ to 10 ⁻¹ s ⁻¹ is controlled within a certain range, both extrudability from the nozzle and sagging property can be achieved.

JP-A-60-235875 JP-A-60-31349 JP-A-61-252280 Japanese Patent No. 3420920 JP 2001-302709 A

Journal of the Adhesion Society of Japan Vol.41 No. 11 (2005) P.430-P.435

  However, in the methods described in Patent Documents 1 to 4 above, polyvinyl alcohol having a low polymerization degree is added in any case. In such a case, these polyvinyl alcohols are added in seed polymerization. New emulsion particles are very easily formed in the system by reaction with the monomer. That is, it is known that polyvinyl alcohol with a low saponification degree having a saponification degree of 80 to 89 mol% generally has a high surface activity, and among these, a polyvinyl alcohol with a low polymerization degree is a simple substance such as vinyl acetate. When a reaction by a polymerization catalyst occurs in the presence of a monomer, new emulsion particles having these polyvinyl alcohols as protective colloids are very easily formed in water. Further, polyvinyl alcohol with a high saponification degree having a saponification degree of 90 to 98 mol% does not have so high surface activity, but with a polyvinyl alcohol with a very low polymerization degree as described in Patent Document 2, Similarly, it is easy to form emulsion particles having these polyvinyl alcohols as protective colloids. Furthermore, since the degree of surface activity is low due to the relatively high degree of saponification, the stability of the emulsion at the time of polymerization is lowered, and in many cases, the particles aggregate to form a gel at the time of polymerization or exhibit abnormal viscosity. Moreover, even if polymerization is possible, an emulsion that is extremely difficult to handle is often generated due to thickening at a low temperature. The ethylene vinyl acetate copolymer resin emulsion to be used often contains these free polyvinyl alcohols, and the above Patent Documents 1 to 4 disclose free polyvinyl in the ethylene vinyl acetate copolymer resin emulsion used as a seed emulsion. Since there is no restriction on alcohol, in the seed polymerization method using the conventional ethylene vinyl acetate copolymer resin emulsion as a seed described in these patent documents, in any case, new emulsion particles are added when seed polymerization is performed. It is difficult to obtain a highly stable emulsion while preventing formation.

  That is, according to the polymerization method using the ethylene-vinyl acetate copolymer resin emulsion described in Patent Documents 1 to 4 as a seed, new emulsion particles are generated in the system in the course of proceeding polymerization. However, this will change the particle size and particle size distribution of the vinyl acetate resin emulsion in which new emulsion particles other than the seed are finally produced. Distribution control becomes difficult. From this, it is considered that the rheological properties of the emulsions obtained by these methods show various properties depending on various polymerization conditions and the composition of the polyvinyl alcohol resin used. This means that it is extremely difficult to control the coatability with vinyl acetate resin emulsions produced by these methods.

  Further, in the polymerization method described in Patent Document 5, particles having polyvinyl alcohol as a protective colloid are generated at the time of polymerization of the core portion, and seed polymerization using seeds is not used in these particle generation processes. It is hard to say that the particle size to be generated can be controlled. In Patent Document 5, a polymerization technique for controlling the high cohesion force of the polymer produced on the core side by preparing a core-shell emulsion and the fusing property of the particles by the flexible polymer produced on the shell side of the particle surface is disclosed. The main focus is on the control of particle size and particle size distribution.

  In addition, Non-Patent Document 1 does not describe the polymerization conditions for generating very fine vinyl acetate resin-based particles in the seed polymerization process, and what method can be used to finely control newly generated particles. Not clear at all. Even if the particle size of the newly produced vinyl acetate resin emulsion can be controlled, the work of finding out the polymerization conditions must be carried out in a number of extremely detailed and precise polymerization experiments, which is economically easy. It can't be done. In addition, the formation of new particles in the seed polymerization process itself is considered to have an extremely large influence on the rheological properties of the system. The generation of new particles in the seed polymerization process also leads to rheological considerations. Since this system is extremely complicated and unclear, it is considered that this system will require a great deal of effort to grasp the correlation between the analysis result of the rheological properties and the polymerization composition. That is, according to these techniques, it is hardly considered that rheological characteristics can be controlled freely and easily by a polymerization composition.

  As described above, the particle size and particle size distribution of the vinyl acetate resin emulsion is still not sufficiently controlled, and it is necessary to further control the particle size and particle size distribution in order to improve coatability. There is.

  Also, in paper and woodworking adhesive applications where vinyl acetate resin emulsions are frequently used as adhesives, plasticizers and high-level plasticizers are required from the viewpoints of fire safety and occupational safety, and protection of the global environment. Highly safe adhesives that do not contain solvents such as boiling point solvents and film-forming aids, and have high interest in adhesives that have excellent film-forming properties even at low temperatures of 5 ° C or below, such as in winter. In addition, from the viewpoint of improving the durable adhesive performance of the final adhesive product, in particular, it has high water resistance and heat resistance, which is a weak point of vinyl acetate resin emulsion adhesives, or from the viewpoint of improving the efficiency of the adhesive work Therefore, there is a strong demand for shortening the press time and curing time, and there is a strong demand for a vinyl acetate resin emulsion adhesive that is excellent in water resistance and initial adhesiveness (adhesion strength rise) commensurate with this. Is there is also a problem that is.

  Moreover, in the bonding work site, a roll part of a roll coating machine, which is generally used when applying an adhesive, is washed after the work is completed. The ease of washing of the roll at this time is influenced by the type of adhesive, and is one of the important factors in production efficiency from a practical viewpoint. However, there is a problem that the adhesive remains on the roll and the productivity is lowered.

  Therefore, in order to solve the above problems, the present invention improves the coatability and roll washability, and also provides a vinyl acetate resin emulsion excellent in water resistance, heat resistance, initial adhesiveness, and safety. An object of the present invention is to provide a manufacturing method thereof.

  As a result of diligent studies to solve the above problems, the inventors of the present invention used an ethylene vinyl acetate resin emulsion having a water elution rate of 10% or less as a seed, containing at least vinyl acetate as a monomer, A vinyl acetate resin emulsion comprising a polyvinyl alcohol resin other than a polyvinyl alcohol resin having a saponification degree of less than 90 mol% and an average polymerization degree of 2500 or less as a resin, and having a predetermined value as a span calculation value relating to the particle size distribution of the emulsion. The present invention has been completed by finding that the above problems can be solved.

That is, the vinyl acetate resin emulsion of the present invention is a vinyl acetate resin obtained by polymerizing at least one monomer in the presence of at least one polyvinyl alcohol resin, using ethylene vinyl acetate copolymer resin emulsion as a seed. The water-elution rate of the coating of the ethylene vinyl acetate copolymer resin emulsion is 10% or less, the monomer is vinyl acetate, and the polyvinyl alcohol resin has a saponification degree of 90 mol%. It is a polyvinyl alcohol resin other than the polyvinyl alcohol resin having an average polymerization degree of 2500 or less and a span calculation value defined by the following formula (1) is 1.0 or less.
Span calculation value = | cumulative frequency% diameter A−cumulative frequency% diameter B | ÷ median diameter (μm) (1)
Here, the cumulative frequency% diameter A is the particle diameter (μm) of the vinyl acetate resin emulsion when the cumulative frequency during measurement is 10%, and the cumulative frequency% diameter B is 90% of the cumulative frequency during measurement. The particle diameter (μm) and median diameter of the vinyl acetate resin emulsion at the time when the accumulative frequency is 50% indicate the particle diameter (μm) of the polyvinyl acetate resin emulsion, and the symbol || Indicates the value.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the vinyl acetate resin-type emulsion which was excellent in water resistance and heat resistance, initial adhesiveness, and roll washability while improving coatability.

Hereinafter, embodiments of the present invention will be described in detail.
The vinyl acetate resin emulsion of the present invention is a vinyl acetate resin emulsion obtained by polymerizing at least one monomer in the presence of at least one polyvinyl alcohol resin, using ethylene vinyl acetate copolymer resin emulsion as a seed. It is intended.

  The seed used in the present invention is an ethylene vinyl acetate copolymer resin emulsion. The ethylene content of the ethylene vinyl acetate copolymer resin emulsion is 10 to 50% by weight, preferably 15 to 40% by weight. If the amount is less than 10% by weight, the film formability of the emulsion produced by seed polymerization is difficult to obtain, and if it exceeds 50% by weight, the normal adhesive strength and heat resistant adhesive strength of the emulsion produced by seed polymerization are reduced.

  Further, the solid content of the ethylene vinyl acetate copolymer resin emulsion is 50% by weight or more of the total solid content of the vinyl acetate resin emulsion produced by the present seed polymerization method when the monomer is only vinyl acetate, preferably, 55 to 65% by weight. If the solid content of the ethylene-vinyl acetate copolymer resin emulsion is less than 50% by weight, the film-forming property of the emulsion produced by seed polymerization is lowered at low temperatures, and the addition of a plasticizer and the like is further reduced, resulting in reduced safety. Because it does. The monomer is a monomer copolymerizable with vinyl acetate, and the homopolymer Tg of the monomer is −45 ° C. or less, and the copolymerizable monomer can be copolymerized When the total amount of the monomer and vinyl acetate is 25% by weight or more, the solid content of the ethylene vinyl acetate copolymer resin emulsion used is the total content of the vinyl acetate resin emulsion produced by this seed polymerization method. It is 10 weight% or more of solid content, Preferably it is 20-60 weight%. This is because if the solid content of the ethylene vinyl acetate copolymer resin emulsion is less than 10% by weight, the particle size of the emulsion produced by seed polymerization tends to be large, the polymerization stability is lowered, and the storage stability is lowered.

The ethylene vinyl acetate copolymer resin emulsion has a water elution rate of 10% or less, preferably 5% or less. Here, the water elution rate is defined by the following equation (1).
Water elution rate (%) = {(absolute dry weight g of film before water immersion treatment−absolute dry weight g of film after water immersion treatment) / absolute dry weight g of film before water immersion treatment} × 100 (1 )
Specifically, the ethylene vinyl acetate copolymer resin emulsion is taken so that the thickness of the dried film is approximately 1 mm, and dried in a hot air circulating thermostat at 50 ± 3 ° C. for 3 days or more. Make it. Exactly 5 pieces are cut out from each dried sample into a 2 cm × 2 cm square shape to form test pieces. Immediately after heat-treating each test piece in a hot air circulating drier at 105 ± 3 ° C. for 3 hours or more, the weight (g) of the coating is measured to 4 digits after the decimal point to obtain the absolute dry weight before the water immersion treatment. Next, the dried test piece is completely immersed in distilled water, and this is left in a constant temperature room at 23 ± 3 ° C. for 2 weeks for water immersion treatment. With respect to the film after the water immersion treatment, the absolute dry weight is measured in the same manner as described above to obtain the absolute dry weight of the film after the water immersion treatment. When the water elution rate is larger than 10%, the particle size distribution of the emulsion produced by seed polymerization becomes wide, and it becomes difficult to control the coating property, and the initial adhesion performance and roll cleaning property are lowered. In general ethylene vinyl acetate copolymer resin emulsions using polyvinyl alcohol as a protective colloid, polyvinyl alcohol with a low saponification degree and a low polymerization degree, which is easily dissolved in water, dissolves in distilled water during water immersion treatment. Therefore, a large water elution rate means that it contains a large amount of free polyvinyl alcohol having a low saponification degree and a low polymerization degree.

  The ethylene vinyl acetate copolymer resin emulsion itself used as a seed emulsion preferably has a span calculation value of 1.0 or less. Further, the particle diameter of the vinyl acetate resin emulsion produced by the present invention is preferably in the range of 0.5 to 4.0 μm in median diameter, and more preferably in the range of 0.8 to 3.0 μm. Is preferred. If the particle size is less than 0.5 μm in median size, the initial adhesiveness, detergency and coatability are likely to deteriorate, and if the particle size is greater than 4.0 μm in median size, the storage stability of the emulsion is increased due to particle sedimentation. This is because it tends to decrease.

  The monomer added to the seed emulsion is vinyl acetate, and other monomers copolymerizable with vinyl acetate can be used as necessary. Other monomers include carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, fumaric acid, and crotonic acid, and anhydrides thereof, and unsaturated dibasic acid monoalkyl esters such as monomethyl maleate and monomethyl itaconate. Amide group-containing monomers such as diacetone acrylamide, acrylamide, dimethyl acrylamide, N-methylol acrylamide, N-vinyl-2-pyrrolidone, acetyl group-containing monomers such as allyl alcohol, dimethylallyl alcohol, isopropenyl allyl acetate , Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, α-olefins such as ethylene, sodium allyl sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, etc. One or two kinds of crosslinkable monomers such as cold dimethacrylate, hexanediol (meth) acrylate, trimethylolpropane tri (meth) acrylate, (meth) acrylic acid ester, vinyl ester, vinyl ether, and alkoxysilane having an unsaturated bond More than one species can be used. As the (meth) acrylic acid ester, a conventionally known (meth) acrylic acid ester can be used. Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( (Meth) acrylic acid alkyl esters such as octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxy (meth) acrylate Alkoxyalkyl (meth) acrylates such as ethyl, hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate, methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, propoxymethyl (meth) acrylate , Glycidyl (meth) acrylate, etc. Glycidyl group-containing (meth) acryl acid ester.

  As the vinyl ester, a known vinyl ester other than vinyl acetate can be used. Specific examples include aliphatic formic acid vinyl esters such as vinyl formate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl octylate, and benzoic acid. Mention may be made of aromatic carboxylic acid esters such as vinyl.

  Moreover, conventionally well-known vinyl ether can be used as vinyl ether. Specific examples include alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, and isopropyl vinyl ether.

  Examples of the alkoxysilane having an unsaturated bond include vinylacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, and other vinylalkoxysilanes, γ- (meth) acryloxypropyltrimethoxysilane, Examples thereof include (meth) acryloxyalkylalkoxysilanes such as γ- (meth) acryloxypropyltriethoxysilane and γ- (meth) acryloxypropyltriethoxysilane.

  The monomer other than vinyl acetate has a homopolymer Tg (glass transition temperature) of −45 ° C. or lower, preferably −50 ° C. or lower. This is because when the glass transition temperature is higher than −45 ° C., the film formability at a low temperature is lowered, so that a plasticizer or the like needs to be added and the safety is lowered. In addition, the use of a monomer having a Tg (glass transition temperature) of the homopolymer of −45 ° C. or lower improves adhesion to materials other than paper and wood, but the homopolymer has a glass transition temperature of −45. This is because, when the temperature is higher than 0 ° C., the adhesion to materials other than paper and wood materials such as plastic films also decreases.

  As monomers other than vinyl acetate, (meth) acrylic acid alkyl ester, (meth) acrylic acid alkoxyalkyl, glycidyl group-containing (meth) acrylic acid ester, vinylalkoxysilane and (meth) acryloxy At least one of alkylalkoxysilanes, more preferably (meth) acrylic acid alkyl ester, glycidyl group-containing (meth) acrylic acid ester and at least one of vinylalkoxysilane, more preferably (meth) acrylic acid alkyl ester and A combination of a glycidyl group-containing (meth) acrylic acid ester, or a combination of a (meth) acrylic acid alkyl ester and a vinylalkoxysilane. By copolymerizing vinyl alkoxysilane or (meth) acryloxyalkylalkoxysilane, the water resistance and heat resistance of the coating film of the vinyl acetate resin emulsion can be further improved. Vinylalkoxysilane is copolymerized with other monomers so that the alkoxysilane group is pendant to the seed polymerization polymer chain, and the alkoxysilane group further reacts to form a crosslinked structure between the polymer chains. Form. When hydrolysis of the alkoxy group occurs during seed polymerization, cross-linking is formed between polymer chains, resulting in a decrease in film formability. Therefore, the vinyl alkoxysilane preferably has an alkoxy group that is difficult to hydrolyze. Such vinyl alkoxysilane preferably has, for example, a methoxyethoxy group or a propoxy group as an alkoxy group. Examples of such vinyl alkoxysilane include vinyl tris (2-methoxyethoxy) silane.

  The monomer other than vinyl acetate is 25% by weight or more and 80% by weight or less, preferably 30% by weight or more and 60% by weight or less, based on the total amount of monomers including vinyl acetate and the other monomers. is there. This is because if it is less than 25% by weight, the film formability at a low temperature is lowered. Moreover, it is because the adhesiveness to plastic films other than paper and a woody material also falls.

  Moreover, the solid content of the whole monomer which combined vinyl acetate and this other monomer is 5 times or less of the solid content of an ethylene vinyl acetate copolymer resin emulsion, Preferably it is 2.5 times or less. This is because when the amount is more than 5 times, the normal state adhesive strength and heat resistant adhesive strength of the emulsion produced by seed polymerization are lowered.

  For the protective colloid of the vinyl acetate resin emulsion of the present invention, a polyvinyl alcohol resin is used. Polyvinyl alcohol resins include polyvinyl alcohol obtained by saponifying polyvinyl acetate, acetoacetyl group-modified polyvinyl alcohol obtained by acetoacetylating the polyvinyl alcohol, ethylene group-modified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, etc. Modified polyvinyl alcohol. The polyvinyl alcohol resin used in the present invention is not particularly limited as long as it is a polyvinyl alcohol resin other than a polyvinyl alcohol resin having a saponification degree of less than 90 mol% and an average polymerization degree of 2500 or less, but preferably has a saponification degree of 90 mol%. A polyvinyl alcohol resin having an average polymerization degree of less than 2500 and / or a saponification degree of 90 mol% or more can be used.

  The amount of the polyvinyl alcohol resin is 0.1 to 19.9% by weight, preferably 0.3 to 10.0% by weight, based on the entire vinyl acetate resin emulsion (total solid content). If it is less than 0.1% by weight, the stability of the emulsion is lowered, and if it is more than 19.9% by weight, the viscosity of the emulsion is increased, the coating property is lowered, and the water-resistant adhesive strength is also liable to be lowered. is there.

  The vinyl acetate resin emulsion of the present invention is not particularly limited except for the above conditions, and can be produced using a known seed polymerization method. For example, an ethylene vinyl acetate copolymer resin emulsion is previously present in the polymerization tank before the reaction, and in the presence of one or more types of polyvinyl alcohol resin, polymerization of vinyl acetate and a copolymerizable monomer is started. A method of performing emulsion polymerization by adding together with an agent can be used. As the polymerization initiator, a polymerization initiator such as an azo polymerization initiator, hydrogen peroxide, or ammonium persulfate can be used. Further, these polymerization initiators may be used in combination with a reducing agent and used as a redox polymerization initiator. For example, hydrogen peroxide can be used with tartaric acid, L-ascorbic acid, and the like, and ammonium persulfate can be used with sodium hydrogen sulfite, sodium hydrogen carbonate, and the like.

  The solid content concentration of the resulting vinyl acetate resin emulsion is not particularly limited, but is 30 to 70% by weight, preferably 40 to 60% by weight. If it is less than 30% by weight, the viscosity of the emulsion produced by seed polymerization becomes low and it becomes difficult to obtain the desired viscosity, or the stability is lowered and it is easy to separate into two phases. This is because it becomes difficult to increase the viscosity of the emulsion and it is difficult to obtain a highly stable emulsion.

  The minimum film-forming temperature (MFT) of the resulting vinyl acetate resin emulsion is 30 ° C. or lower, preferably 20 ° C. or lower. More preferably, it is 2 degrees C or less. If it is 2 degrees C or less, the film formability in low temperature can be ensured, without adding solvents, such as a plasticizer. On the other hand, if it is higher than 30 ° C., it is difficult to obtain a coating film having sufficient strength, or it is difficult to obtain a highly safe emulsion because it is necessary to add a solvent such as a plasticizer in a use environment near room temperature. Because.

  The resulting vinyl acetate resin emulsion has a viscosity of 100 to 200,000 mPa · s at 23 ° C., preferably 1,000 to 100,000 mPa · s. If it is less than 100 mPa · s, it will be difficult to ensure the smoothness of the coating film and control the thickness, and if it is more than 200,000 mPa · s, it will be difficult to produce and transport, and also to ensure the smoothness of the coating film and control the thickness. Because it becomes difficult.

In addition, the obtained vinyl acetate resin emulsion has a viscosity index represented by the following formula of 3 or more, preferably 4 to 8.
Viscosity index = shear stress (Pa) at a shear rate of 7000 (1 / s) / shear stress (Pa) at a shear rate of 500 (1 / s)
This viscosity index corresponds to the thixotropic index and is an index representing the degree of structural viscosity. In the present invention, if it is less than 3, the viscosity under a high shear rate is lowered and the workability is improved, but it becomes difficult to control the smoothness of the coating film and the film thickness, which is not preferable. In particular, it is difficult to ensure the film thickness during high-speed coating.

  Moreover, you may add a conventionally well-known additive to the vinyl acetate type-resin emulsion of this invention as needed. For example, a plasticizer, a pH adjuster, a thickener, an antiseptic, an antifoaming agent, a wetting agent, a filler, a suspending agent and the like can be mentioned. As described above, the vinyl acetate resin emulsion of the present invention has an MFT of 30 ° C. or less without adding a plasticizer, but a plasticizer may be added as necessary.

  Moreover, you may add a silane coupling agent as an additive. When a glycidyl group-containing (meth) acrylic acid ester is used as a monomer, a silane coupling agent having a monofunctional functional group having reactivity with a glycidyl group is added to the polymer after seed polymerization. Thus, the glycidyl group and the silane coupling agent react to form a structure in which the alkoxysilane group is pendant to the seed polymerization polymer chain, and the alkoxysilane group further reacts to finally form a crosslinked structure between the polymer chains. Thereby, the water resistance of a coating film can be improved. A silane coupling agent that can react with a glycidyl group is used. For example, alkoxysilane having a mercapto group such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) Examples include alkoxysilanes having amino groups such as aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, and alkoxysilanes having imino groups such as 3- (N-phenyl) aminopropyltrimethoxysilane. be able to. If necessary, a silane coupling agent having no reactivity with the glycidyl group as described above can be freely used as long as the effect of the invention is not hindered.

  EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not limited to a following example. The “parts” below are “parts by weight” unless otherwise specified. The materials used are shown in Table 1 below.

Reference Example 1
558 parts of water was placed in a reaction vessel equipped with a stirrer, and 42 parts of J Poval JP-33 were added thereto while being dispersed, and then the reaction vessel was heated to 90 ° C. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling to 50 ° C., 170 parts of Sumikaflex 450HQ was added. Further, 0.5 parts of sodium acetate and 0.5 part of L-tartaric acid were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 55-60 ° C., a catalyst (a mixture of 0.05 part of 35% hydrogen peroxide and 10 parts of water) was added to initiate the reaction. After reacting for 10 to 20 minutes, 570 parts of vinyl acetate monomer and catalyst (0.12 part of 35% hydrogen peroxide are mixed with 100 parts of water while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C. Were added dropwise over about 3 hours and 30 minutes to cause a reaction. After completion of dropping, the mixture was heated to 85 ° C. and aged for 2 hours, and then cooled to room temperature to obtain an emulsion having a concentration of 49.7%, a viscosity at 23 ° C. of 18,720 mPa · s, and a pH of 4.7. .

(Evaluation method)
Although an evaluation method is demonstrated below, it carried out similarly about the following Example and the comparative example.
Measurement of water elution rate The water elution rate was measured using the method described above. That is, an ethylene-vinyl acetate copolymer resin emulsion was taken so that the thickness of the dried film was approximately 1 mm, and the film was dried in a hot air circulating thermostat at 50 ± 3 ° C. for 3 days or more. Five test pieces were cut out from each dried sample exactly into a 2 cm × 2 cm square shape. Next, immediately after each test piece was heat-treated in a hot air circulating drier at 105 ± 3 ° C. for 3 hours or more, the weight (g) of the film was measured to 4 digits after the decimal point to obtain the absolute dry weight before the water immersion treatment. . Subsequently, the dried test piece was completely immersed in distilled water, and this was left in a constant temperature room at 23 ± 3 ° C. for 2 weeks to perform a water immersion treatment. With respect to the film after the water immersion treatment, the absolute dry weight was measured in the same manner as described above to obtain the absolute dry weight of the film after the water immersion treatment. And the water elution rate was computed using the above-mentioned Formula (1).

2. Measurement of average particle size and particle size distribution The average particle size of the sample was defined as the median size measured using a laser diffraction / scattering particle size distribution measuring apparatus LA-950V2 (manufactured by Horiba, Ltd.). In addition, a span calculation represented by the following formula is performed as an index indicating the particle size distribution at this time, and when this value is less than 1.0, an emulsion having a narrow particle size distribution is obtained, and when the value is 1.0 or more, the particle size is represented. It was determined as an emulsion having a wide distribution. In addition, the refractive index of the polyvinyl acetate resin was used for the measurement.
Span calculation value = | cumulative frequency% diameter A−cumulative frequency% diameter B | ÷ median diameter (μm)
Here, the cumulative frequency% diameter A is the particle diameter (μm) of the vinyl acetate resin emulsion (also referred to as a sample) when the cumulative frequency during measurement is 10%, and the cumulative frequency% diameter B is the cumulative frequency during measurement. The particle diameter (μm) of the vinyl acetate resin emulsion when 90% is reached, and the median diameter is the particle diameter (μm) of the vinyl acetate resin emulsion when the cumulative frequency is 50%. || indicates an absolute value.

3. Measurement of viscosity index HAAKE rotational viscometer RV20 type (manufactured by Eihiro Seiki Co., Ltd.) is used as a viscosity index of the sample, and the shear rate is 0 to 10,000 (1 / s) at a sample liquid temperature of 23 ° C. for 2 minutes and 30 seconds. The viscosity graph was measured under increasing conditions. The ratio of the shear stress (Pa) at a shear rate of 500 (1 / s) and the shear stress (Pa) at a shear rate of 7000 (1 / s), represented by the following formula, was used as the viscosity index of the sample. .
Viscosity index = shear stress (Pa) at a shear rate of 7000 (1 / s) / shear stress (Pa) at a shear rate of 500 (1 / s)

4). MFT measurement The MFT (minimum film-forming temperature) of the sample was measured using an MFT measuring device (manufactured by Tester Sangyo Co., Ltd.). In addition, the measurement made MFT the temperature of the minimum of the transparent film which each sample formed into a film.

5. Coating property The sample was coated on a commercially available vinyl chloride film at a speed of about 1 second in an area of 5 cm in width and 30 cm in length using an applicator having a coating thickness of 25 μm in an emulsion state. Each sample was applied five times, and each sample was dried at room temperature to obtain a test specimen. Moreover, about the film thickness (micrometer) of the coating sample after drying, by subtracting the thickness of a vinyl chloride sheet from the thickness which combined the vinyl chloride sheet and the coating sample film | membrane using the micrometer, it is 6 for each test body. It was determined by measuring the points and calculating the average of these measured values for a total of 30 points on all five test specimens. The difference between the theoretical coating thickness (μm) shown by the following formula and the coating film thickness (μm) of each sample actually measured using a micrometer is within 20% of the theoretical coating thickness (μm). The sample that was a good coating property that can control the film thickness was marked as ◯. In addition, a sample having 20 to 40% was evaluated as Δ, and a sample having a difference larger than 40% was evaluated as ×, thereby indicating a sample having poor coatability.

Theoretical coating thickness (μm) = {Gap of applicator 25 (μm) × Specific gravity of each sample × Solid content (%) of each sample}
However, the specific gravity of each sample was calculated as 1.07.
Moreover, the solid content of each sample used the value measured by making it dry for 1 hour using a 105 degreeC dryer.

6). Evaluation of roll washability Each sample was coated on a glass plate using an applicator so that the thickness was 125 μm, the width was 5 cm, and the length was 15 cm. Immediately after that, the glass plate was placed at an angle of 55 to 65 ° from the horizontal plane with respect to flowing water (water temperature 20 to 25 ° C.) falling vertically from 1800 to 2200 ml per minute from a height of 5 cm. The time (seconds) from immediately after the coated sample was brought into contact with water until all the sample coated on the glass plate was washed was measured using a stopwatch. The case where these times (seconds) are less than the following times set according to the respective viscosity (mPa · s) measured at 23 rpm and 20 rpm is ×, As evaluated.

7). Evaluation of initial adhesion The initial adhesion performance of the sample was measured under the following conditions using an initial adhesion tester ASM-01 / 05 (manufactured by JT Toshi Co., Ltd.). The case where the adhesive strength reached 20 N / cm ² or more within 5 seconds and paper breakage occurred was evaluated as “◯”, and the other cases were evaluated as “X”. However, for samples with an MFT of 10 ° C or higher, phenylglycol plasticizer phenylglycol H is 6 parts by weight per 100 parts by weight of the solid content of the sample, and for samples with an MFT of 5-10 ° C, phenylglycol H is sampled. The measurement was performed by adding 3 parts by weight per 100 parts by weight of the solid content of the sample, and the sample having an MFT of 0 to 5 ° C. was measured as it was.
(1) Measurement conditions Measurement temperature: 23-26 ° C atmosphere
Substrate: Kraft paper / Craft paper
Application amount: 40 (g / m ² )
Open time: 0.5 (seconds)
Press pressure: 0.05 (MPa)
Press time: 1-6 (seconds)
(2) Evaluation Each of 6 levels with a press time of 1 to 6 seconds was measured for shear adhesive strength and visually checked for paper breakage.

8). Evaluation of normal adhesiveness Using a cover block (length 30 mm x width 25 mm x thickness 10 mm) conforming to JIS standards, the sample was bonded under the following bonding conditions so that the bonding area was 6.25 cm ² Five pieces were made for each sample. The test piece was subjected to a compression test at a crosshead speed of 3 mm / min using a tensile tester AG-5000B type (manufactured by Shimadzu Corporation) immediately after curing. The value obtained by dividing the maximum strength (N) at that time by the adhesion area was defined as the normal adhesion strength (N / mm ² ) of the sample. However, for samples with an MFT of 10 ° C. or higher, phenyl glycol H is 6 parts by weight per 100 parts by weight of the solid content of the sample, and for samples with an MFT of 5 to 10 ° C., phenyl glycol H is 100 weight parts of the sample. Measurement was performed by adding 3 parts by weight per part, and the measurement was performed with the sample having an MFT of 0 to 5 ° C. as it was.
Adhesion condition Application amount: Application on both sides of 75 g / m2 on each side Open deposition time / Closed deposition time: 30 seconds or less Clamping: 20-25 ° C. 1.0 MPa 16 hours Curing: 20-25 ° C., relative humidity 50-60% Below 1 week

9. Evaluation of water-resistant adhesion Five test pieces each having a cover block adhered thereto were prepared in the same manner as in the evaluation of normal adhesion. The test piece was immersed in a water bath at 60 ± 3 ° C. for 3 hours, and then immediately immersed in water at 20 to 25 ° C. for 15 minutes to cool. Thereafter, a compression test was performed at a crosshead speed of 3 mm / min using a tensile tester (AG-5000 type: manufactured by Shimadzu Corporation). The value obtained by dividing the maximum strength (N) at that time by the adhesion area was taken as the water-resistant adhesion strength (N / mm ² ) of the sample. However, for samples with an MFT of 10 ° C. or higher, phenyl glycol H is 6 parts by weight per 100 parts by weight of the solid content of the sample, and for samples with an MFT of 5 to 10 ° C., phenyl glycol H is 100 weight parts of the sample. Measurement was performed by adding 3 parts by weight per part, and the measurement was performed with the sample having an MFT of 0 to 5 ° C. as it was.

10. Evaluation of heat-resistant adhesion Five test pieces each having a cover block bonded thereto were prepared for each sample in the same manner as in the evaluation of normal and water-resistant adhesive properties. This test piece was left in an 80 ° C. constant temperature box AGS-100A accessory (manufactured by Shimadzu Corporation) for 1 hour. Immediately after taking out, a compression test was performed at a crosshead speed of 3 mm / min using a tensile tester AG-5000 type (manufactured by Shimadzu Corporation) in the same manner as the evaluation of water-resistant adhesion. The value obtained by dividing the maximum strength (N) at that time by the adhesion area was defined as the heat-resistant adhesion strength (N / mm ² ) of the sample. However, for samples with an MFT of 10 ° C. or higher, phenyl glycol H is 6 parts by weight per 100 parts by weight of the solid content of the sample, and for samples with an MFT of 5 to 10 ° C., phenyl glycol H is 100 weight parts of the sample. Measurement was performed by adding 3 parts by weight per part, and the measurement was performed with the sample having an MFT of 0 to 5 ° C. as it was.

11. Evaluation of Storage Stability 250 g of a sample was taken in a glass bottle that could be sealed and left in a hot air circulating dryer at 50 ± 3 ° C. for 4 weeks. The viscosity and pH before and after this treatment were measured, and the viscosity change rate and the pH change rate were calculated according to the following formulas. The viscosity change rate at this time is in the range of 0.7 to 1.3, and the pH change rate is in the range of 0.8 to 1.2. Those that did not fall within the above range in either the viscosity change rate or the pH change rate were evaluated as x as an emulsion having poor storage stability. The viscosity was measured at a liquid temperature of 23 ° C. at 10 rpm with a BH type rotational viscometer, and the pH was measured using a pH meter at a liquid temperature of 23 ° C.
Viscosity change rate = sample viscosity after storage stability treatment (mPa · s) / sample viscosity before storage stability treatment (mPa · s)
pH change rate = sample pH after storage stability treatment / sample pH before storage stability treatment

Reference Example 2
Manufactured using the same method as in Reference Example 1 except that Pegar 1900 is used instead of Sumikaflex 450HQ, and the concentration is 49.9%, the viscosity at 23 ° C. is 26,850 mPa · s, and the pH is 4.8. An emulsion was obtained.

Reference Example 3
Manufactured using the same method as in Reference Example 1 except that 340 parts of Sumikaflex 450HQ was added, and an emulsion having a concentration of 50.3%, a viscosity of 11220 mPa · s at 23 ° C., and a pH of 4.7 was obtained. It was.

Reference Example 4
Manufactured using the same method as in Reference Example 1 except that Panflex OM-4200NT was used instead of Sumikaflex 450HQ, the concentration was 49.6%, the viscosity at 23 ° C. was 33,900 mPa · s, and the pH was 4. .8 emulsion was obtained.

Reference Example 5
Manufactured using the same method as in Reference Example 1 except that Sumikaflex 400HQ was used instead of Sumikaflex 450HQ, the concentration was 49.7%, the viscosity at 23 ° C. was 24,350 mPa · s, and the pH was 4.7. An emulsion was obtained.

Reference Example 6
Manufactured using the same method as in Reference Example 1 except that pre-treated Polysol AD56 was used instead of Sumikaflex 450HQ, and the viscosity at a concentration of 50.5% and 23 ° C. was 29,400 mPa · s, pH. Gave an emulsion of 4.8.

Reference Example 7
Manufactured using the same method as in Reference Example 1 except that Sumikaflex 355HQ was used instead of Sumikaflex 450HQ, and the viscosity at a concentration of 49.8% and 23 ° C. was 9,920 mPa · s, An emulsion having a pH of 4.7 was obtained.

Reference Example 8
J POVAL JP-33 Manufactured using the same method as in Reference Example 1 except that 21 parts of J POVAL JP-33 and 21 parts of PVA CST were used instead of 42 parts, and the concentration was 49.8% at 23 ° C. An emulsion having a viscosity of 13,560 mPa · s and a pH of 4.7 was obtained.

Reference Example 9
Manufactured using the same method as in Reference Example 1 except that 21 parts of J Poval JP-33 and 21 parts of J Poval JM-23 were used instead of 42 parts of J Poval JP-33, and the concentration was 49.9%. An emulsion having a viscosity at 23 ° C. of 15,800 mPa · s and a pH of 4.7 was obtained.

Reference Example 10
J POVAL JP-33 Manufactured using the same method as in Reference Example 1 except that 21 parts of J POVAL JP-33 and 21 parts of J POVAL JM-26 were used instead of 42 parts, and the concentration was 49.8%. An emulsion having a viscosity at 23 ° C. of 18,800 mPa · s and a pH of 4.7 was obtained.

Reference Example 11
J Poval JP-33 Manufactured in the same manner as in Reference Example 1 except that 5.3 parts of J Poval JP-33 and 36.7 parts of PVA CST were used instead of 42 parts, and the concentration was 49.9%. An emulsion having a viscosity at 23 ° C. of 10,820 mPa · s and a pH of 4.7 was obtained.

Reference Example 12.
Manufactured using the same method as in Reference Example 1 except that 5.3 parts of J Poval JP-33 and 36.7 parts of J Poval JM-26 were used instead of 42 parts of J Poval JP-33. An emulsion having a viscosity of 8%, a viscosity at 23 ° C. of 7,480 mPa · s, and a pH of 4.7 was obtained.

Comparative Example 1
A reaction vessel was charged with 389.5 parts of water, and this was prepared in the same manner as in Reference Example 1 except that 10.5 parts of PVA 217 was added instead of J Poval JP-33. The concentration was 55.1%. An emulsion having a viscosity at 23 ° C. of 280 mPa · s and a pH of 4.5 was obtained.

Comparative Example 2
The same method as in Reference Example 1 except that 389.5 parts of water was placed in a reaction vessel, 10.5 parts were used instead of 42 parts of J POVAL JP-33, and Pegar 1901 was used instead of SUMIKAFLEX 450HQ. An emulsion having a concentration of 55.7%, a viscosity at 23 ° C. of 6,630 mPa · s, and a pH of 4.6 was obtained.

Comparative Example 3
The same method as in Reference Example 1 except that 389.5 parts of water was placed in a reaction vessel, 10.5 parts were used instead of 42 parts of J Poval JP-33, and Pegar 1902 was used instead of Sumikaflex 450HQ. An emulsion having a concentration of 55.8%, a viscosity at 23 ° C. of 17,680 mPa · s, and a pH of 4.7 was obtained.

Comparative Example 4
Manufactured using the same method as in Reference Example 1 except that PVA 217 was used instead of J-Poval JP-33, the concentration was 49.7%, the viscosity at 23 ° C. was 10,040 mPa · s, and the pH was 4. An emulsion of 8 was obtained.

Comparative Example 5
Manufactured using the same method as in Example 1 except that PVA 224 was used instead of J Poval JP-33, the concentration was 49.9%, the viscosity at 23 ° C. was 12,540 mPa · s, and the pH was 4. An emulsion of 7 was obtained.

Comparative Example 6
Manufactured using the same method as in Reference Example 1 except that PVA 224 was used in place of J-Poval JP-33 and Pegar 1901 was used in place of Sumikaflex 450HQ. Viscosity at a concentration of 50.1% at 23 ° C Was an emulsion having a pH of 4.7.

Comparative Example 7
Manufactured using the same method as in Reference Example 1 except that PVA CST was used instead of J-Poval JP-33 and Pegar 1901 was used instead of Sumikaflex 450HQ, and the viscosity at a concentration of 49.1% at 23 ° C. Of 5,440 mPa · s and a pH of 4.7 were obtained, but it showed dilatant viscosity and was abnormal in viscosity.

Comparative Example 8.
Using J Poval JP-23 in place of the J Poval JP-33, except for using Pegaru 1901 instead of Sumikaflex 450HQ was prepared in the same manner as in Reference Example 1. When cooled to room temperature, the emulsion aggregated.

As is clear from Tables 2 and 3, using the ethylene vinyl acetate copolymer resin emulsion in which the water elution rate of the coating of the ethylene vinyl acetate copolymer resin emulsion as in Reference Examples 1 to 12 is 10% or less, the degree of saponification is In an example produced by a seed polymerization method using only a polyvinyl alcohol resin other than a polyvinyl alcohol resin having an average polymerization degree of 2500 or less and less than 90 mol%, using vinyl acetate as a monomer, Although MFT showed a high value and water resistance and heat-resistant adhesion performance showed a slightly low value, the particle size distribution indicated by the span calculation value was very narrow and the viscosity index showed a high value. Moreover, all evaluations of coating property, roll cleaning property, and initial adhesiveness were acceptable. On the other hand, an ethylene vinyl acetate copolymer resin emulsion having a water elution rate of more than 10% in the film of the ethylene vinyl acetate copolymer resin emulsion as in Comparative Examples 1 to 8 is used, or the average polymerization is performed with a saponification degree of less than 90 mol%. In the production example produced by the seed polymerization method including a polyvinyl alcohol resin having a degree of 2500 or less, the polymerization stability is extremely high in an example produced by adding only a polyvinyl alcohol resin having a saponification degree of 90 mol% or more. It was bad and an emulsion with good stability could not be obtained. Further, in all other examples, the viscosity index shows a low value, and the particle size distribution indicated by the span calculation value shows a value larger than 1.0 in all examples, and an emulsion having a wide particle size distribution is obtained. Generated. Moreover, all MFT was high and it was unsuccessful in any evaluation of coating property, roll washability, and initial stage adhesiveness. Furthermore, although normal adhesiveness showed a high value, water resistance and heat resistance performance also showed low values.

Reference Example 13
In a reaction vessel equipped with a stirrer, 538.5 parts of water was added, and 31.5 parts of J Poval JP-33 was added thereto while being dispersed, and then the reaction vessel was heated to 90 ° C. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 340 parts of SUMIKAFLEX 450HQ were added. Further, 0.5 parts of sodium acetate and 0.5 part of L-tartaric acid were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 55-60 ° C., a catalyst (a mixture of 0.05 part of 35% hydrogen peroxide and 10 parts of water) was added to initiate the reaction. After reacting for 10 to 20 minutes, 550 parts of vinyl acetate monomer and catalyst (0.12 part of 35% hydrogen peroxide are mixed with 100 parts of water while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C. Were added dropwise over about 3 hours and 30 minutes to cause a reaction. After completion of dropping, the mixture was heated to 85 ° C. and aged for 2 hours, and then cooled to room temperature to obtain an emulsion having a concentration of 50.0%, a viscosity at 23 ° C. of 5,460 mPa · s, and a pH of 4.9. .

Reference Example 14
The reaction vessel was charged with 258.5 parts of water, except that 550 parts of vinyl acetate monomer and catalyst were added dropwise over about 3 hours and 30 minutes, but 200 parts of vinyl acetate monomer and catalyst were added dropwise over about 2 hours. An emulsion having a concentration of 46.6%, a viscosity at 23 ° C. of 13,060 mPa · s, and a pH of 4.9 was obtained using the same method as in Reference Example 13.

Reference Example 15.
It was manufactured using the same method as in Reference Example 14 except that 400 parts of Sumikaflex 450HQ was added instead of 340 parts, the concentration was 47.4%, the viscosity at 23 ° C. was 7,730 mPa · s, and the pH was 4. 9 emulsions were obtained.

Example 1 .
400 parts of Sumikaflex 450HQ was added instead of 340 parts, and 550 parts of vinyl acetate monomer and catalyst were added dropwise over about 3 hours and 30 minutes, but 130 parts of vinyl acetate monomer and catalyst were added over about 1 hour and 30 minutes. The emulsion was prepared in the same manner as in Reference Example 14 except that it was added dropwise to obtain an emulsion having a concentration of 43.4%, a viscosity at 23 ° C. of 5,020 mPa · s, and a pH of 4.9.

Example 2 .
J POVAL JP-33 Manufactured in the same manner as in Example 1 except that 21 parts of J POVAL JP-33 and 21 parts of J POVAL JM-26 were used instead of 31.5 parts, and the concentration was 44.5. %, An emulsion having a viscosity of 14,120 mPa · s at 23 ° C. and a pH of 4.9 was obtained.

Reference Example 16 .
J Poval JP-33 Manufactured in the same manner as in Example 1 except that 21 parts of J Poval JP-33 and 42 parts of PVA CST were used instead of 31.5 parts, and the concentration was 46.3%, 23 An emulsion having a viscosity at 32 ° C. of 32,050 mPa · s and a pH of 4.9 was obtained.

Comparative Example 9
Manufactured in the same manner as in Reference Example 13 except that 360 parts of Pegar 1901 was used instead of 340 parts of Sumikaflex 450HQ, the viscosity at 23 ° C. was 5480%, the viscosity was 12,480 mPa · s, and the pH was An emulsion of 4.9 was obtained.

Comparative Example 10
368.5 parts of water to be put into the reaction vessel was used, except that 550 parts of vinyl acetate monomer and catalyst were dropped over about 3 hours 30 minutes, but 200 parts of vinyl acetate monomer and catalyst were dropped over about 2 hours. An emulsion having a concentration of 42.9%, a viscosity at 23 ° C. of 9,860 mPa · s, and a pH of 4.9 was obtained using the same method as in Reference Example 13.

Comparative Example 11
It was manufactured using the same method as in Comparative Example 10 except that 420 parts of Pegar 1901 was added instead of 360 parts. The concentration was 43.4%, the viscosity at 23 ° C. was 10,360 mPa · s, and the pH was 4.9. An emulsion was obtained.

Comparative Example 12
In the same manner as in Comparative Example 11, except that 200 parts of vinyl acetate monomer and the catalyst were dropped over about 2 hours, 130 parts of vinyl acetate monomer and the catalyst were dropped over about 1 hour and 30 minutes. An emulsion having a concentration of 40.3%, a viscosity at 23 ° C. of 6,420 mPa · s, and a pH of 5.0 was obtained.

Comparative Example 13
Manufactured using the same method as in Comparative Example 12, except that PVA217 was used instead of J-POVAL JP-33, the concentration was 40.7%, the viscosity at 23 ° C. was 2,610 mPa · s, and the pH was 4.8. An emulsion was obtained.

Comparative Example 14
Manufactured using the same method as in Comparative Example 12 except that PVA220 was used instead of J-Poval JP-33, the concentration was 41.0%, the viscosity at 23 ° C. was 3,150 mPa · s, and the pH was 4.7. An emulsion was obtained.

As is clear from Tables 4 and 5, ethylene vinyl acetate copolymer having a water elution rate of 10% or less of the coating of the ethylene vinyl acetate copolymer resin emulsion as in Reference Examples 13 to 15, 16 and Examples 1 and 2. Using a resin emulsion, using a polyvinyl alcohol-based resin having a saponification degree of less than 90 mol% and an average polymerization degree of greater than 2500, using only vinyl acetate as a monomer, and changing the ratio of the monomer to the total solid content In the example produced by the seed polymerization method, the MFT tends to decrease as the amount of the monomer with respect to the total solid content decreases, and the ratio of the monomer to the total solid content is less than 50%. Showed a low value. In these examples, the film forming property was excellent even at a low temperature of 5 ° C. or less without using a solvent such as a plasticizer. Further, the normal state and heat-resistant adhesion performance of these examples were practical values comparable to those of the production examples having high MFTs shown in Table 2. In all the production examples shown in Table 4, the span calculation value was 1.0 or less, the particle size distribution was very narrow, and the viscosity index showed a high value, as in the production example shown in Table 2. . Moreover, all evaluations of coating property, roll cleaning property, and initial adhesiveness were acceptable. Furthermore, in Table 3, a polyvinyl alcohol resin having a degree of saponification of less than 90 mol% and an average polymerization degree of greater than 2500 was used in a system using only a polyvinyl alcohol resin having a saponification degree of 90 mol% or more, which produced an emulsion lacking in polymerization stability. It can be seen that in a system in which a small amount of is used in combination, the polymerization stability is improved and a highly stable emulsion is produced. In contrast, an ethylene vinyl acetate copolymer resin emulsion in which the water elution rate of the ethylene vinyl acetate copolymer resin emulsion film exceeds 10% is used, and a polyvinyl alcohol resin having a saponification degree of less than 90 mol% and an average polymerization degree of 2500 or less. In Comparative Examples 9 to 14 manufactured by the seed polymerization method including the above, the MFT tendency showed the same tendency as the manufacturing example in Table 4, but the viscosity index showed a low value, and the span calculation value was The particle size distribution shown was a value greater than 1.0 in all examples, and an emulsion having a wide particle size distribution was produced. Moreover, it was a result including the rejection by any evaluation of coating property, roll washability, and initial stage adhesiveness. However, in the production examples shown in Tables 4 and 5, the water resistance and heat resistant adhesion performance were slightly low, and particularly the water resistance adhesion performance was low.

Example 3 .
458.5 parts of water was put into a reaction vessel equipped with a stirrer, and 31.5 parts of J Poval JP-33 was added thereto while being dispersed, and then the reaction vessel was heated to 90 ° C. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 380 parts of SUMIKAFLEX 450HQ was added. Further, 0.5 parts of sodium acetate and 0.5 part of L-tartaric acid were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 55-60 ° C., a catalyst (a mixture of 0.05 part of 35% hydrogen peroxide and 10 parts of water) was added to initiate the reaction. After reacting for 10 to 20 minutes, while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C., a mixed monomer of 325 parts of vinyl acetate monomer and 125 parts of n-butyl acrylate monomer and a catalyst (35% excess) Hydrogen oxide (0.21 part mixed with 100 parts water) was added dropwise over about 3 hours to react. After completion of dropping, the mixture was heated to 85 ° C. and aged for 2 hours, and then cooled to room temperature to obtain an emulsion having a concentration of 49.7%, a viscosity at 23 ° C. of 27,600 mPa · s, and a pH of 4.8. .

Example 4 .
Add 558.5 parts of water to the reaction vessel, add 260 parts instead of 380 parts of SUMIKAFLEX 450HQ, and add about 325 parts of vinyl acetate monomer and 125 parts of n-butyl acrylate monomer and catalyst over about 3 hours The mixture was prepared in the same manner as in Example 3 except that a mixed monomer of 400 parts of vinyl acetate monomer and 150 parts of n-butyl acrylate monomer and a catalyst were dropped over about 3 hours 30 minutes. An emulsion having a concentration of 49.4%, a viscosity at 23 ° C. of 36.750 mPa · s, and a pH of 4.6 was obtained.

Example 5 .
In addition to 380 parts of Sumikaflex 450HQ, 340 parts were added, and instead of adding a mixed monomer of 325 parts of vinyl acetate monomer and 125 parts of n-butyl acrylate monomer and the catalyst over about 3 hours, 285 parts of vinyl acetate monomer And 165 parts of a mixed monomer of n-butyl acrylate monomer and a catalyst were added dropwise over about 2 hours, using the same method as in Example 3 , with a concentration of 47.7% and a viscosity at 23 ° C. of 76 , 400 mPa · s, and an emulsion having a pH of 4.7.

Comparative Example 15
518.5 parts of water to be added to the reaction vessel was added, 400 parts of Pegal 1901 was added instead of 380 parts of Sumikaflex 450HQ, and a mixed monomer of vinyl acetate monomer and n-butyl acrylate monomer and catalyst were dropped over about 3 hours. It was manufactured using the same method as in Example 3 except that it was dropped over about 3 hours and 30 minutes instead of, and the viscosity at a concentration of 48.6%, 23 ° C. was 61,000 mPa · s, and the pH was An emulsion of 4.8 was obtained.

Comparative Example 16.
618.5 parts of water to be added to the reaction vessel was added, 280 parts of Pegal 1901 were added instead of 380 parts of Sumikaflex 450HQ, and about 3 parts of a mixed monomer of 325 parts of vinyl acetate monomer and 125 parts of n-butyl acrylate monomer and the catalyst were added. It was manufactured using the same method as in Example 3 except that instead of the dropwise addition over time, a mixed monomer of 400 parts of vinyl acetate monomer and 150 parts of n-butyl acrylate monomer and a catalyst were dropped over about 2 hours. An emulsion having a concentration of 48.1%, a viscosity at 23 ° C. of 94,600 mPa · s, and a pH of 4.8 was obtained.

Comparative Example 17
478.5 parts of water to be added to the reaction vessel was added, 360 parts of Pegal 1901 were added instead of 380 parts of Sumikaflex 450HQ, and about 3 parts of a mixed monomer of 325 parts of vinyl acetate monomer and 125 parts of n-butyl acrylate monomer and the catalyst were added. In place of the dropwise addition over time, a mixture of 285 parts of vinyl acetate monomer and 165 parts of n-butyl acrylate monomer and a catalyst were added in the same manner as in Example 3 except that the mixture was dropped over about 2 hours. An emulsion having a concentration of 49.7%, a viscosity at 23 ° C. of 105,800 mPa · s, and a pH of 4.8 was obtained.

Comparative Example 18.
Manufactured using the same method as in Comparative Example 17 except that PVA217 was used instead of J-Poval JP-33, the concentration was 48.2%, the viscosity at 23 ° C. was 48,800 mPa · s, and the pH was 4.4. An emulsion was obtained.

Comparative Example 19.
Manufactured using the same method as in Comparative Example 17 except that PVA220 was used instead of JPOVAL JP-33, the concentration was 49.6%, the viscosity at 23 ° C. was 62,400 mPa · s, and the pH was 4.5. An emulsion was obtained.

As is clear from Tables 6 and 7, an ethylene vinyl acetate copolymer resin emulsion having a water elution rate of 10% or less of the coating film of the ethylene vinyl acetate copolymer resin emulsion was used, and the average degree of polymerization was at least less than 90 mol%. Includes a polyvinyl alcohol resin larger than 2500, and includes vinyl acetate and a monomer copolymerizable with vinyl acetate, and the copolymerizable monomer homopolymer has a Tg of −45 ° C. or less. The polymerizable monomer is 25% by weight or more of the total monomer including the copolymerizable monomer and vinyl acetate, and the solid content of the whole monomer is the ethylene vinyl acetate copolymer. In Examples 3 and 5 produced by the seed polymerization method so that the solid content of the resin emulsion was 3 times or less, the MFT showed a low value. In these examples, the film forming property was excellent even at a low temperature of 5 ° C. or less without using a solvent such as a plasticizer. In Example 20, where the solid content of the whole monomer was 3 times or more of the solid content of the ethylene-vinyl acetate copolymer resin emulsion, the MFT increased to 4 ° C. and the film formability at a low temperature. Decreased. The normal state and heat-resistant adhesion performance of these examples were practical values comparable to the production examples shown in Tables 2 and 4. In all the production examples shown in Table 6, the span calculation value is 1.0 or less, the particle size distribution is very narrow, and the viscosity index is a high value as in the production examples shown in Table 2 and Table 4. showed that. Moreover, all evaluations of coating property, roll cleaning property, and initial adhesiveness were acceptable. In contrast, an ethylene vinyl acetate copolymer resin emulsion in which the water elution rate of the ethylene vinyl acetate copolymer resin emulsion film exceeds 10% is used, and a polyvinyl alcohol resin having a saponification degree of less than 90 mol% and an average polymerization degree of 2500 or less. In Comparative Examples 15 to 19 manufactured by the seed polymerization method including MFT, MFT is a value less than that of the manufacturing examples in Table 6, and any sample has excellent film forming properties at a low temperature of 5 ° C. or lower. However, all of the viscosity indexes showed a low value, and the particle size distribution indicated by the span calculation value showed a value larger than 1.0 in all examples, and an emulsion having a wide particle size distribution was produced. Moreover, it was a result including the rejection by any evaluation of coating property, roll washability, and initial stage adhesiveness. In addition, in the production examples shown in Table 6, water resistance and heat resistant adhesion performance were slightly improved, whereas in the production examples shown in Table 7, no significant improvement was observed in heat resistance and water resistance adhesion performance.

Example 6 .
Into a reaction vessel equipped with a stirrer, 608.5 parts of water was added, and 21 parts of J-Poval JP-33 and 10.5 parts of Goosephimer Z320 were added thereto, and then the reaction vessel was heated to 90 ° C. did. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 380 parts of SUMIKAFLEX 450HQ was added. Further, 0.5 part of sodium acetate and 0.3 part of anhydrous sodium bisulfite were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 50 to 55 ° C., a catalyst (a mixture of 0.35 part ammonium persulfate and 10 parts water) was added to initiate the reaction. After reacting for 10 to 20 minutes, while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C., a mixed monomer of 325 parts of vinyl acetate monomer and 125 parts of n-butyl acrylate monomer and a catalyst (ammonium persulfate 0 .About.35 parts mixed with 100 parts water) was added dropwise over about 3 hours to react. After completion of the dropwise addition, the mixture was heated to 85 ° C. and aged for 2 hours and then cooled to room temperature. Further, 0.5 part of anhydrous sodium bisulfite was added, and stirring was continued for 1 hour to obtain a concentration of 45.0% at 23 ° C. An emulsion having a viscosity of 63,200 mPa · s and a pH of 4.7 was obtained.

Reference Example 17
Into a reaction vessel equipped with a stirrer, 608.5 parts of water was added, and 21 parts of J-Poval JP-33 and 10.5 parts of Gohsephimer Z320 were added thereto, and then the reaction vessel was heated to 90 ° C. Heated. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 380 parts of SUMIKAFLEX 450HQ was added. Further, 0.5 part of sodium acetate and 0.3 part of anhydrous sodium bisulfite were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 50 to 55 ° C., a catalyst (a mixture of 0.35 part ammonium persulfate and 10 parts water) was added to initiate the reaction. After reacting for 10 to 20 minutes, while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C., 450 parts of vinyl acetate monomer and catalyst (mixed with 0.35 part of ammonium persulfate and 100 parts of water) Was added dropwise over about 3 hours 30 minutes to react. After completion of dropping, the mixture was heated to 85 ° C. and aged for 2 hours, and then 40 parts of PHG-H and 0.5 part of anhydrous sodium bisulfite were added as a plasticizer, and stirring was continued for 1 hour and cooled to room temperature. An emulsion having a concentration of 46.4%, a viscosity at 23 ° C. of 35,400 mPa · s, and a pH of 4.6 was obtained.

Example 7 .
Into a reaction vessel equipped with a stirrer, 258.5 parts of water was added, 21 parts of J Poval JP-33 and 10.5 parts of Gohsephimer Z320 were added thereto, and then the reaction vessel was heated to 90 ° C. did. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 400 parts of Sumikaflex 450HQ was added. Further, 0.5 part of sodium acetate and 0.3 part of anhydrous sodium bisulfite were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 50 to 55 ° C., a catalyst (a mixture of 0.35 part ammonium persulfate and 10 parts water) was added to initiate the reaction. After reacting for 10 to 20 minutes, 130 parts of vinyl acetate monomer and catalyst (mixed with 0.35 part of ammonium persulfate and 100 parts of water) while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C. Was reacted dropwise over about 2 hours. After completion of the dropwise addition, the mixture was heated to 85 ° C. and aged for 2 hours, and then cooled to room temperature. Further, 0.5 part of anhydrous sodium bisulfite was added and stirring was continued for 1 hour to obtain a concentration of 43.1%, 23 ° C. An emulsion having a viscosity of 10,280 mPa · s and a pH of 4.8 was obtained.

Comparative Example 20.
Manufactured using the same method as in Example 6 except that 400 parts of Pegar 1901 were added instead of 380 parts of Sumikaflex 450HQ, the viscosity was 59,600 mPa · s, and the pH at 23 ° C. was 55.7%. An emulsion of 4.8 was obtained.

Comparative Example 21.
Manufactured using the same method as in Reference Example 17 except that 400 parts of Pegar 1901 were added instead of 380 parts of Sumikaflex 450HQ, the viscosity was 46.9%, the viscosity at 23 ° C. was 37,300 mPa · s, and the pH was An emulsion of 4.6 was obtained.

Comparative Example 22.
Manufactured using the same method as in Example 7 except that 420 parts of Pegar 1901 were added instead of 400 parts of SUMIKAFLEX 450HQ, the viscosity was 44.5%, the viscosity at 23 ° C. was 11,560 mPa · s, and the pH was An emulsion of 4.8 was obtained.

As is apparent from Tables 8 and 9, an ethylene vinyl acetate copolymer resin emulsion having a water elution rate of 10% or less of the coating film of the ethylene vinyl acetate copolymer resin emulsion was used, and the average polymerization degree was less than 90 mol%. In Examples 6 and 7 and Reference Example 17 , which were produced by seed polymerization including polyvinyl alcohol resin other than polyvinyl alcohol resin of 2500 or less and acetoacetyl group-modified polyvinyl alcohol resin having a saponification degree of 90 mol% or more 4 and MFT showed the low value like the manufacture example shown in Table 6. In these examples, the film forming property was excellent even at a low temperature of 5 ° C. or lower. The normal state and heat-resistant adhesion performance of these examples were practical values comparable to the production examples shown in Tables 2 and 4. Further, in all the production examples shown in Table 8, the span calculation value is 1.0 or less as in the production examples shown in Table 2, Table 4, and Table 6, the particle size distribution is very narrow, and the viscosity index Showed a high value. Moreover, all evaluations of coating property, roll cleaning property and initial adhesiveness were acceptable. On the other hand, the comparative example manufactured using the ethylene vinyl acetate copolymer resin emulsion in which the water elution rate of the coating film of the ethylene vinyl acetate copolymer resin emulsion exceeds 10%, and other than the examples shown in Table 8 In 20-22, although MFT showed the low value similarly to the manufacture example of Table 8, and although all the samples showed the result excellent in the film formability in the low temperature of 5 degrees C or less, all the viscosity index | exponents The particle size distribution indicated by a low value and indicated by the calculated span value was greater than 1.0 in all examples, and an emulsion having a wide particle size distribution was produced. Moreover, it was a result including the rejection by any evaluation of coating property, roll washability, and initial stage adhesiveness. Further, in the production examples shown in Table 8, the water resistance and heat resistant adhesion performance were slightly improved, whereas in the production examples shown in Table 9, the water resistance adhesion performance was low. However, it can be seen that Reference Example 17 and Comparative Example 21 have a low safety because they contain a plasticizer. Safety other than these production examples is high in that it does not contain a plasticizer.

Example 8 .
Into a reaction vessel equipped with a stirrer, 608.5 parts of water was added, and 31.5 parts of J Poval JP-33 was added thereto while being dispersed, and then the reaction vessel was heated to 90 ° C. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 380 parts of SUMIKAFLEX 450HQ was added. Further, 0.5 part of sodium acetate and 0.2 part of anhydrous sodium bisulfite were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 50 to 55 ° C., a catalyst (a mixture of 0.35 part ammonium persulfate and 10 parts water) was added to initiate the reaction. After reacting for 10 to 20 minutes, mixing 295 parts of vinyl acetate monomer, 125 parts of n-butyl acrylate monomer and 30 parts of glycidyl methacrylate monomer while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C. A monomer and a catalyst (a mixture of 0.35 part of ammonium persulfate and 100 parts of water) were dropped over about 3 hours to be reacted. After completion of the dropwise addition, the mixture was heated to 85 ° C. and aged for 2 hours, and then cooled to room temperature. Further, 0.2 part of anhydrous sodium bisulfite was added and stirring was continued for 1 hour to obtain a concentration of 45.4% at 23 ° C. An emulsion having a viscosity of 19,800 mPa · s and a pH of 4.5 was obtained. Further, 1.5 parts of A-189 is added to 100 parts of this emulsion at room temperature (20-25 ° C.), the concentration is 45.7%, the viscosity at 23 ° C. is 15,400 mPa · s, and the pH is 4. .5 emulsion was obtained.

Example 9 .
Manufactured using the same method as in Example 8 except that 1.9 parts of A-1891 was used instead of A-189, the viscosity at a concentration of 45.8%, 23 ° C. was 16,850 mPa · s, pH An emulsion of 4.5 was obtained.

Example 10 .
Manufactured using the same method as in Example 8 except that 2.0-9 parts of Y-9669 was used instead of A-189, the viscosity at a concentration of 46.1% and 23 ° C. was 19,150 mPa · s, pH. An emulsion of 5.3 was obtained.

Example 11
Manufactured using the same method as in Example 8 except that 1.0 part of Y-9669 was used instead of A-189, the viscosity at a concentration of 45.9%, 23 ° C. was 18,650 mPa · s, pH Of 5.0 was obtained.

Example 12 .
Manufactured using the same method as in Example 8 except that 3.0 parts of Y-9669 was used instead of A-189, the viscosity at a concentration of 46.6%, 23 ° C. was 19,600 mPa · s, pH An emulsion of 5.3 was obtained.

Example 13 .
Into a reaction vessel equipped with a stirrer, 608.5 parts of water was added, and J Poval JP-33 was added thereto while being dispersed, and then the reaction vessel was heated to 90 ° C. The mixture was stirred for 90 minutes to obtain an aqueous polyvinyl alcohol solution. After cooling this to 50 ° C., 380 parts of SUMIKAFLEX 450HQ was added. Further, 0.5 part of sodium acetate and 0.2 part of anhydrous sodium bisulfite were added and dissolved, and then 50 parts of vinyl acetate monomer was added and stirred for 15 minutes or more. While heating this to 80 ° C., when the internal temperature reached 50 to 55 ° C., a catalyst (a mixture of 0.35 part ammonium persulfate and 10 parts water) was added to initiate the reaction. After reacting for 10 to 20 minutes, while adjusting the temperature so that the internal temperature becomes 77 to 83 ° C., a mixture of 320 parts of vinyl acetate monomer, 130 parts of n-butyl acrylate monomer and 10 parts of A-172 A monomer and a catalyst (a mixture of 0.35 part of ammonium persulfate and 100 parts of water) were dropped over about 3 hours to be reacted. After completion of the dropwise addition, the mixture was heated to 85 ° C. and aged for 2 hours and then cooled to room temperature. Further, 0.2 part of anhydrous sodium bisulfite was added and stirring was continued for 1 hour to obtain a concentration of 44.5% at 23 ° C. An emulsion having a viscosity of 15,140 mPa · s and a pH of 4.5 was obtained.

Comparative Example 23.
Manufactured using the same method as in Example 8 except that 400 parts of Pegar 1901 was used instead of Sumikaflex 450HQ, the concentration was 47.1%, the viscosity at 23 ° C. was 28,950 mPa · s, and the pH was 4. An emulsion of 7 was obtained.

Comparative Example 24.
Manufactured using the same method as in Example 9 except that 400 parts of Pegar 1901 was used instead of Sumikaflex 450HQ, the concentration was 47.4%, the viscosity at 23 ° C. was 31,450 mPa · s, and the pH was 4. An emulsion of 5 was obtained.

Comparative Example 25.
Manufactured using the same method as in Example 10 except that 400 parts of Pegar 1901 was used instead of Sumikaflex 450HQ, the concentration was 47.6%, the viscosity at 23 ° C. was 32,100 mPa · s, and the pH was 5. An emulsion of 0 was obtained.

Comparative Example 26.
Manufactured using the same method as in Example 11 except that 400 parts of Pegar 1901 was used instead of Sumikaflex 450HQ, the concentration was 47.3%, the viscosity at 23 ° C. was 28,400 mPa · s, and the pH was 5. An emulsion of 0 was obtained.

Comparative Example 27.
Manufactured using the same method as in Example 12 except that 400 parts of Pegal 1901 was used instead of Sumikaflex 450HQ, the concentration was 47.8%, the viscosity at 23 ° C. was 29,500 mPa · s, and the pH was 5. An emulsion of 2 was obtained.

Comparative Example 28.
Manufactured using the same method as in Example 13 except that 400 parts of Pegar 1901 was used instead of Sumikaflex 450HQ, the concentration was 46.0%, the viscosity at 23 ° C. was 26,450 mPa · s, and the pH was 4. 6 emulsions were obtained.

As is apparent from Tables 10 and 11, an ethylene vinyl acetate copolymer resin emulsion having a water elution rate of 10% or less of the coating film of the ethylene vinyl acetate copolymer resin emulsion is used, and the average polymerization degree is less than 90 mol%. A polyvinyl alcohol resin other than a polyvinyl alcohol resin that is 2500 or less, and a monomer containing a vinyl acetate and a monomer containing an alkoxysilyl group-containing monomer as a monomer copolymerizable with vinyl acetate. Example in which a silane compound having a functional group capable of reacting with a glycidyl group is further added to a vinyl acetate resin emulsion produced by a seed polymerization method and containing a glycidyl group-containing monomer. 8-13 in Table 4, showed a MFT lower values in the same manner as in the production example shown in Table 6 and Table 8. In these examples, the film forming property was excellent even at a low temperature of 5 ° C. or less without using a solvent such as a plasticizer. The normal state and heat-resistant adhesion performance of these examples were extremely high values as compared with the production examples shown in Table 2, Table 4, Table 6, and Table 8. In all the production examples shown in Table 10, the span calculation value is 1.0 or less and the particle size distribution is very narrow as in the production examples shown in Tables 2, 4, 6, and 8. The viscosity index showed a high value. Moreover, all evaluations of coating property, roll cleaning property and initial adhesiveness were acceptable. On the other hand, the comparative example manufactured using the ethylene vinyl acetate copolymer resin emulsion in which the water elution rate of the film of the ethylene vinyl acetate copolymer resin emulsion exceeds 10%, and otherwise manufactured in the same manner as shown in Table 10 In 25-30, MFT shows a low value like the manufacture example of Table 10, and the result which was excellent in the film formability in the low temperature of 5 degrees C or less without using solvents, such as a plasticizer, in any sample. However, all of the viscosity indexes showed a low value, and the particle size distribution indicated by the span calculation value showed a value larger than 1.0 in all examples, and an emulsion having a wide particle size distribution was produced. Moreover, it was a result including the rejection by any evaluation of coating property, roll washability, and initial stage adhesiveness. In addition, in the production example shown in Table 10, the heat-resistant adhesion performance was extremely improved and the water-resistant adhesion performance was improved, whereas in the production example shown in Table 11, the heat-resistant adhesion performance was improved, but the water-resistant adhesion performance was improved. All showed low values. Further, as shown in Table 10, the addition amount of the silane compound having a functional group capable of reacting with the glycidyl group added to the vinyl acetate resin emulsion produced by the seed polymerization method including the glycidyl group-containing monomer. It can be seen that various performances do not change greatly even when the value is changed, and excellent results are obtained in any of the evaluation items.

  As described above, in the examples, the coating property, the initial adhesiveness, and the roll cleaning property were excellent. On the other hand, in the comparative example, those characteristics were inadequate.

  The vinyl acetate resin emulsion of the present invention has excellent coating properties and roll cleaning properties, as well as excellent water resistance, heat resistance, and initial adhesiveness. It can be used in a wide variety of fields such as ceramic binders, and paper or woodworking adhesives.

Claims (8)

A vinyl acetate resin emulsion obtained by polymerizing at least one monomer in the presence of at least one polyvinyl alcohol resin, using ethylene vinyl acetate copolymer resin emulsion as seed particles,
The water elution rate of the film of the ethylene vinyl acetate copolymer resin emulsion is 10% or less,
The monomer includes vinyl acetate and a monomer copolymerizable with vinyl acetate,
The polyvinyl alcohol resin is a polyvinyl alcohol resin other than a polyvinyl alcohol resin having a saponification degree of less than 90 mol% and an average polymerization degree of 2500 or less,
The span calculation value defined by the following formula (1) is 1.0 or less,
The particle diameter of the vinyl acetate resin emulsion is in the range of 0.5 to 4.0 μm in terms of median diameter,
The concentration of the polyvinyl alcohol-based resin is 0.1 to 19.9% by weight of the total solid content,
A vinyl acetate resin emulsion in which the solid content of the whole monomer, which is a combination of vinyl acetate and the copolymerizable monomer, is 5 times or less the solid content of the ethylene vinyl acetate copolymer resin emulsion.
Span calculation value = | cumulative frequency% diameter A−cumulative frequency% diameter B | ÷ median diameter (μm) (1)
(Here, the cumulative frequency% diameter A is the particle diameter (μm) of the vinyl acetate resin emulsion when the cumulative frequency during measurement is 10%, and the cumulative frequency% diameter B is 90% of the cumulative frequency during measurement. The particle diameter (μm) and median diameter of the vinyl acetate resin emulsion when the cumulative frequency becomes 50%, the particle diameter (μm) of the polyvinyl acetate resin emulsion when the cumulative frequency reaches 50%. Indicates absolute value.) Claim 1 Symbol placement of vinyl acetate resin emulsion containing an average degree of polymerization of at least saponification degree is less than 90 mol% is 2500 greater than polyvinyl alcohol resins. The vinyl acetate resin emulsion according to claim 2 , further comprising a polyvinyl alcohol resin having a saponification degree of 90 mol% or more. The vinyl acetate resin emulsion according to claim 3, wherein the polyvinyl alcohol resin having a saponification degree of 90 mol% or more is acetoacetyl group-modified polyvinyl alcohol. Tg of the homopolymer of the copolymerizable monomer is −45 ° C. or less, and the copolymerizable monomer is the entire monomer including the copolymerizable monomer and vinyl acetate. 25 is a weight% or more, the solid content of the ethylene-vinyl acetate copolymer resin emulsion is not less than 10% by weight of total solids of the vinyl acetate resin emulsion, according to claim 1, wherein the vinyl acetate resin emulsion. Wherein as monomer other than vinyl acetate, (meth) acrylic acid ester and / or claim 1, wherein the vinyl acetate resin emulsion containing a glycidyl group-containing monomer. The vinyl acetate resin emulsion according to claim 6 , further comprising a silane coupling agent capable of reacting with a monomer containing a clicidyl group. A method for producing the vinyl acetate resin emulsion according to claim 1 ,
An ethylene vinyl acetate resin emulsion having a water elution rate of 10% or less as the ethylene vinyl acetate copolymer resin emulsion is used, and vinyl acetate and a monomer copolymerizable with vinyl acetate are used as the monomers. A method for producing a vinyl acetate resin emulsion, wherein a polyvinyl alcohol resin other than a polyvinyl alcohol resin having a saponification degree of less than 90 mol% and an average polymerization degree of 2500 or less is used as the polyvinyl alcohol resin.