JPS5843408B2 - emulsion material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the reaction operation of emulsion polymerization is easy, and the obtained emulsion has good viscosity stability and applicability. The present invention relates to a method for producing a vinyl or acrylic polymer emulsion, which is more hydrophobic than vinyl acetate, and which can be formed into a coating film with excellent water resistance and heat resistance by heating or adding a crosslinking agent.

The inventors previously discovered that a copolymer of α-olefin and maleic anhydride made water-soluble with a basic substance is an excellent emulsion stabilizer for vinyl acetate emulsions, and also contributes to improving the stability and physical properties of emulsions. They discovered that this was the case, and filed a patent application for a "polyvinyl acetate emulsion composition" (Japanese Patent Application No. 104912/1982).

The present inventors further conducted research and emulsified a polymer of inbutylene and maleic anhydride (hereinafter abbreviated as A) by adding a basic substance to the carboxyl group in an amount of 0.3 i or more to make it water-soluble. As a result of emulsion polymerization of various monomers and comonomers as stabilizers, we have found that even with hydrophobic monomers such as styrene and alkyl methacrylate, stable emulsions can be obtained through simple emulsion polymerization operations, and the excellent coating film described above can also be obtained. It was found that this could be done, leading to the completion of the present invention.

Conventionally, nonionic and anionic surfactants have been used as emulsifiers in emulsion polymerization of hydrophobic monomers.
Since the selection of the emulsifier and the polymerization conditions are difficult, in order to obtain a stable emulsion, the monomer is emulsified with a portion of the emulsifier in advance, and this is dropped into the reaction system for polymerization. is complex and the resulting emulsion generally has a low viscosity.

In order to obtain a highly viscous emulsion, water-soluble polymers such as cellulose derivatives are added to the polymer emulsion, or components containing carboxyl groups are copolymerized in advance, and a basic substance is added afterwards to soften the surface of the emulsion particles. Methods used have been to increase the viscosity by solubilizing or by adding soluble and hydrophobic solvents to the polymer emulsion, but these methods are time-consuming and the physical properties of the polymer emulsion change due to these additives. was unavoidable.

Moreover, even when these methods are used for polymer emulsions made of extremely hydrophobic monomers, the thickening effect is lower than that for polymer emulsions made of hydrophilic monomers.

In the present invention, when a basic substance is added to A in an amount of 0.3 equivalent or more based on the carboxyl group to make it water-solubilized and used as an emulsion stabilizer, it does not affect the water solubility of the monomer at all ( Emulsion polymerization can be easily carried out using the monomer dropping method, and a stable polymer emulsion can be obtained.

Moreover, an emulsion of any viscosity can be obtained depending on the degree of polymerization and the amount of A added.

Furthermore, the emulsion obtained by this method has good physical stability such as low-temperature fluidity, and good applicability such as low foaming property.

Furthermore, since the emulsion stabilizer A can be crosslinked by adding a crosslinking agent or copolymerizing a crosslinkable monomer, a coating film with excellent water resistance and heat resistance can be obtained.

The copolymer of isobutylene and maleic anhydride used in the present invention, that is, A is a copolymer obtained by a conventional polymerization method of isobutylene and maleic anhydride. This is a maleic acid copolymer sold by Imbutylene Kanmizu, which is commercially available from Kikikuraray.

Basic substances added to make A water-soluble include caustic alkali, alkali carbonate, ammonium carbonate, ammonia, organic amines, alkali acetate, and ammonium acetate.

For water droplets, caustic alkali and ammonia are particularly preferred.

The amount of these added needs to be 0.3 equivalent or more relative to the carboxyl group.

If the amount is less than 0.3 equivalent, A cannot be completely solubilized in water, and if the amount of basic substance added is increased, A can be easily solubilized in water, but the pH of the aqueous solution becomes high and emulsion polymerization is impaired. It's getting worse.

Therefore, the amount of basic substance added is 0.
It is 3 equivalents or more, preferably 0.3 to 0.5 equivalents.

The degree of polymerization of A is closely related to the viscosity of an aqueous solution and greatly influences the viscosity of an emulsion obtained by emulsion polymerization, but is not particularly defined in the present invention.

In addition, the concentration of A also greatly influences the viscosity of the emulsion and its physical properties.

Generally, the concentration of A is at least 2% by weight of the emulsion, preferably at least 3% by weight.

If the amount is less than 2% by weight, it becomes difficult to obtain a stable emulsion.

In the present invention, commonly used emulsion stabilizers can also be used in combination.

That is, various surfactants are used as emulsifiers, and water-soluble polymers such as cellulose derivatives and polyvinyl alcohol are used as protective colloids.

The amount of these added is preferably 50% by weight or less based on A.

If it is added in an amount of 50% by weight or more, it is not preferable because it gives an unstable emulsion, deteriorates the physical properties of the emulsion, and deteriorates performance such as water resistance of the coating film.

The monomers used in the present invention are vinyl and acrylic monomers, and are particularly effective for more hydrophobic monomers than vinyl acetate.

Acrylic monomers that are more hydrophobic than vinyl acetate include alkyl methacrylates, alkyl acrylates,
These are derivative compounds having various functional groups.

The polymerization method for obtaining the emulsion composition of the present invention is as follows:
Since the most common polymerization method of adding a polymerization initiator to an aqueous solution of A or A and a general emulsion stabilizer and polymerizing monomers dropwise can be adopted, the reaction operation is very simple.

Further, depending on the type of monomer, special polymerization methods such as pressure polymerization may be employed.

Potassium persulfate and ammonium persulfate are particularly preferred as polymerization initiators.

The emulsion concentration of the present invention is within the range of 25-65%,
It can be changed as appropriate depending on the purpose.

Additionally, additives can be added during or before or after emulsion polymerization, if necessary.

These additives include plasticizers, solvents, fillers, and pigments, and in some cases, latex produced by other methods may also be added.

The emulsion composition thus obtained can significantly improve the water resistance and heat resistance of the emulsion coating by heating or adding a crosslinking agent.

Examples of crosslinking agents include polyvalent metal compounds and epoxy compounds that react with the carboxyl group of A.

Thus, the emulsion composition of the present invention can be economically supplied for a wide range of applications such as paints, waterproofing agents, and waxes.

Next, the present invention will be described in more detail with reference to Examples.

Example 1 Ammonia was added to an isobutylene and maleic anhydride copolymer (Isopan 06 manufactured by Rirare) at a concentration of 0 to the carboxyl group.
．． Aqueous solution made by adding 4 equivalents (isopan concentration -10
, 5%) 24M', potassium persulfate 0.1' as an initiator, and a total of 1501 mixtures of various monomers were dropwise polymerized*.

The reaction is completed in about 4 hours at 80-85°C. The resulting emulsion was uniformly applied onto a glass plate and baked at 170° C. for 20 minutes, and the performance of the coating film was as shown in Table 1.

Bond CZ 101 used for comparison is an emulsion with extremely excellent water resistance that is made by copolymerizing styrene and acrylic acid ester with a functional group.

Example 2 Isobutylene-IK water mamalate copolymer isopane 0
Aqueous solution (isopane concentration 25
%) 401 and holoxyethylene nonyl phenyl ether (Neugen E manufactured by Daiichi Kogyo Seiyaku ■) as a general emulsifier.
A170) and polyoxyethylene allyl ether sulfonated into soda salt (Hitenol S manufactured by Daiichi Kogyo Seiyaku ■) mixed at a ratio of 4:1 in terms of solid content were added in the amount shown in Table 2. Further, 1,702 g of water was added to the aqueous solution, and using 1 g of potassium persulfate as an initiator, 40 g of methyl methacrylate, 801 g of butyl acrylate, and 3 g of methacrylic acid were added.
Various emulsions were obtained by dropwise polymerization of mixed monomers containing 10 fI of hydroxypropyl.

These emulsions were applied to a glass plate and heated to 170°C.
The results of heating and baking for 10 minutes are shown in Table 2.

These results show that unless the amount of emulsifier added is less than 50% by weight based on the isobutylene di-bran water maleic acid copolymer, the water resistance of the coating film will be significantly deteriorated.

Example 3 Inbutylene-maleic anhydride copolymer (isopane 04
) and caustic soda in an amount of 0.4 equivalents based on the carboxyl group to make it solubilized (Impane concentration -20%) 400
Using 1.31 g of potassium persulfate as S', a monomer mixture of 45 f of methyl methacrylate and 752 g of butyl acrylate was polymerized dropwise.

A hand emulsion was obtained by reacting at 80*-90°C for 3 hours.

Add 48% caustic soda aqueous solution to this until the amount becomes 0.8 equivalent to the carboxyl group, and then add 1 ml of calcium hydroxide.
201 was added to obtain an adhesive emulsion.

The viscosity of this product was as shown in Table 3 as a result of an adhesive strength test at 11,500 CPS.

Description of test method (compression shear adhesive strength) (1) Normal state; adhesion strength of bar/birch wood based on JIS, 6804 method (2) Water resistance, the test piece from (1) was immersed in water at 30°C for 30 minutes. Adhesive strength immediately after soaking for an hour (3) Heat resistance: The test piece from (1) was immersed in hot water at 60°C for 3 hours.
Adhesion strength immediately after being immersed in cold water at 20°C for 15 minutes (4) Repeated boiling: The test piece from (1) was immersed in boiling water for 4 hours, dried at 60°C for 20 hours, and then immersed in boiling water again for 4 hours. Adhesive strength immediately after immersion in cold water at 20°C for 15 minutes (
5) Heat resistance: Leave the test piece in (1) at 60°C for 1 hour and immediately measure the adhesive strength (initial adhesive strength) Thickness: 1 cIrL, length: 3 crrL, width: 2.5CrfL
Lauan plywood with a thickness of 3%, length of 3.5C771, and width of 2.5 () is pasted on both sides of the lauan material to produce 2.5kg1cr!
After compressing for a specified period of time, measure the splitting adhesion force of a 2.5 cIrL width on the lauan plywood surface using a Schopper testing machine (emulsion used for comparison) Bond CH135 quick-drying vinyl acetate emulsion Bond TSIIO phenol-modified vinyl acetate emulsion, exclusive use Example of adding 5% curing agent 4 Aqueous solution (isopane concentration -20%) 1 made by adding 0.4 equivalents of ammonia to carboxyl groups to isobutylene-1j + water-maleic acid copolymer (isopane 04)
To 25P, 11' each of sodium dodecylbenzenesulfonate (Neoperex 05, manufactured by Kao Soap) or polyoxyethylene nonylphenyl ether (Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) was used as an emulsifier, and to this, 100 g of butyl acrylate and 1 part of ammonium persulfate were added. .51 and 401' of ion-exchanged water were added, and when the internal temperature rose to 80°C, the remaining butyl acrylate 4001 was continuously added over 1 hour.

During this time, the internal temperature was maintained at 80° C. and 8 CC of 10% ammonium persulfate solution was added in four portions.

After the addition of butyl acrylate is completed, the temperature is maintained at 80° C. for about 10 minutes to complete the polymerization.

After the polymerization is completed, the mixture is cooled and the pH is adjusted to 5 to 6 with aqueous ammonia.

The viscosity and adhesion properties of these emulsions are shown in Table 4 in comparison to emulsions without isopane.

Description of test method (i) Emulsion viscosity; using BL type viscometer, 30°C,
Measured at 60 RPM (ii) Freezing stability: Restoration state when returned to room temperature after being left in a refrigerator at -15°C for 16 hours ○...Restored to the original emulsion ×...
・・A layer that blocks and does not restore to an emulsion Adhesion to aluminum plate; ○ Cast the emulsion on an aluminum plate that has been treated with acetone to remove surface dirt and dry at 100°C.

After that, a piece of cloth is placed and the emulsion is again cast on it and dried at 100°C.

Cut to 0@1.7 CIIL and measure the peel strength in the 90 degree direction using an autograph.

(Tensile speed - 10cm/min, 20℃, 65%RH)
As is clear from Table 4, emulsions using isopane, especially when isopane/danipol is used in combination, have low emulsion viscosity (and excellent freeze stability and adhesion to aluminum plates).

Example 5 Inbutylene-maleic anhydride copolymer (isopan 10
) was made water-solubilized by adding ammonia to the carboxyl group in an amount of 0.4 equivalents (isopane concentration = 15
%) 3305' and potassium persulfate 0152, dropwise polymerization was carried out at 76-77°C for 1 hour, and the reaction was further completed at 90°C for 1 hour.

Adjust the pH of this emulsion to 7 with ammonia, add 33% by weight of calcium carbonate to the emulsion, and add 6% of flour to the emulsion.
7% by weight and 40% by weight of water to give a viscosity of 35,000CPS.
An emulsion composition was obtained.

An adhesion test on a veneer board was conducted using this composition, and the results were as shown in Table 5.

The veneer used was birch wood with a thickness of 0.4X, and the plywood used was lauan plywood (Type I).

Claims (1)

[Claims] 1. A copolymer of inbutylene and maleic anhydride is made water-soluble by adding 0.3 equivalent or more to the carboxyl group of the basic substance copolymer, and is used as an emulsion stabilizer to make the copolymer more hydrophobic than vinyl acetate. 1. A method for producing an emulsion composition, comprising emulsion polymerization of a vinyl monomer or an acrylic monomer.