JPS5887105A - Production of synthetic resin emulsion - Google Patents

Abstract

PURPOSE:To produce a soapless soap synthetic resin emulsion excellent in chemical stability, by emulsion-polymerizing a difficultly water-soluble unsaturated monomer in the production of a MW-lowered starch and an ethylenically unsaturated monomer graft-polymerizable therewith. CONSTITUTION:A difficultly water-soluble monomer (e.g., styrene) is emulsion- polymerized in an aqueous medium containing 10-50wt%, based on the total solids of emulsion produced, MW-lowered starch and 0.5-5wt% ethylenically unsaturated monomer graft-copolymerizable with the starch, e.g., (meth)acrylate ester. EFFECT:This emulsion can be maintained at a stable emulsion state in both the strong acid and strong alkaline ranges and form films excellent in waterproofness. USE:Adhesives, sizes, biodegradable films, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention V′i relates to a method for producing a novel synthetic resin emulsion, which does not use any surfactants or soaps and has particularly excellent chemical stability. Our aim is to provide engineering fusion products at low prices.

Originally, synthetic resin emulsions used soaps such as rosin soap and surfactants as emulsifiers, and if necessary, protective colloids such as polyvinyl alcohol, carboquine methylcellulose, methylcellulose, etc. were added to carry out emulsion polymerization. Is going.

However, in recent years, emphasis has been placed on the physical properties of emulsions after they are formed, and the presence of low-molecular substances such as soaps and surface viscosity particles can cause immigration and impair the performance of the film. There are concerns that it may cause a decrease in water absorption, an increase in water absorption, and a decrease in water resistance.

Unfortunately, when these emulsifiers are mixed into wastewater, they cause foaming, which impedes wastewater treatment operations and causes various other problems.7 Conventionally, these dK problems have been solved. As a rounding method,
The H structure of No-Press, or Nump-Free Efluji, has been developed, and research is being conducted to obtain a stable emulsion.

In many of these studies, hydrophilic functional groups, mainly carboxyl groups, are introduced into Emulgene particles, and a salt thereof is formed to stabilize the particles.

However, this method has the drawback of lacking chemical stability, and improvements in this respect are needed.

As a result of various efforts to obtain a soapless emulsion with particularly excellent chemical stability, the Ministry of the Invention and others have developed low-molecular LFC starch and a small group of ethylenic impurities that are capable of graphing with the starch. By emulsion polymerizing unsaturated monomers that are poorly soluble in water in the presence of saturated monomers, we have created a no-press synthetic resin emul with extremely excellent chemical stability! It was discovered that i-in is produced, and the present invention was completed based on this knowledge.

That is, the present invention emulsion polymerizes an unsaturated monomer in water in the coexistence of a low-molecular-weight treated starch and an ethylenically unsaturated monomer that can be grafted with a UN starch. The treated starch was added in an amount of 10 to 50*jt% of the total solid content in the emulsion, and the starch and the ethylenically unsaturated monomer capable of grafting 6 were added in an amount of 0% to the total solid content in the emulsion.
This is a method for producing a no-press synthetic resin emulsion in which the content is 5 to 5% by weight, and as a result of this method, the hydrophilic starch low-molecular decomposition product plays the role of an emulsifier, and as a result, soaps and surfactants A stable emulsion can be obtained without the presence of.

The low-molecular-weight treated starch used in the present invention refers to a cold-water or hot-water soluble polysaccharide having a glucose unit group, such as potato, sweet potato, corn, wheat, rice, sago, tapioca, or gum, etc. Starch obtained from plant sources such as (this powder can be used regardless of the ratio of its constituent amylose and amyl pectin) to hydrochloric acid, sulfuric acid, formic acid, oxalic acid, etc. ! Oxidizing agents such as acids, periodic acid, ammonium persulfate, perchlorine, sodium perborate, hydrogen peroxide, etc.
It refers to starch that has been reduced in molecular weight by being treated with an enzyme such as CLα-amylase Gin.

In this case, the same effect can be obtained by using naturally occurring gums such as gum arabic, tragacantoga, guar gum, and cast bean gum, algin, and inulin fat instead of starch, but these substances Since the price is high, it is economically disadvantageous and undesirable.

Examples of ethylenically unsaturated monomers that can be grafted onto low-molecular-weight starch include ethylenically unsaturated monomers 1-1 that easily graft with low-molecular-weight starch;
Examples include (meth)acrylic acid, acrinitrile, (meth)acrylamide, and (meth)acrylic acid ester, among which 1'8i or 2's or more is used.

Furthermore, examples of the poorly water-soluble unsaturated monomer that forms the main body of the emulsion include styrene, styrene derivatives,
butadiene, chloroprene, isoprene, imbutene,
Ethylene, vinyl chloride, vinylidene chloride, vinyl acetate, etc. are common. Either one of these or a mixture of two or more unsaturated monomers that can be covalently combined can be used.

In addition, some of the unsaturated monomers that are poorly soluble in water (meth)
Acrylic acid, maleic acid, crotonic acid, itaconic acid, (
A copolymer of an unsaturated polymer easily soluble in water such as meth)acrylamide, N-methylolacrylamide, vinylsulfonic acid, ethyleneimine, glycidyl methacrylate, etc. may also be used.

In order to obtain a stable emulsion by the method of the present invention, the amount of low-molecular starch added and the amount of ethylenically unsaturated monomer that is easily grafted onto the cellulose are important, and the pH constant If the amount added is below or above the range f, no emulsion will be formed, or the particles will rapidly settle, making it impossible to obtain a stable emulsion.

That is, the preferable range of added salmon is such that the low-molecular-weight starch accounts for 10 to 50% of the total solid content in the emulsion.
On the other hand, the amount of the ethylenically unsaturated monomer capable of grafting with the starch is added in an amount of 0.5 to 5 tX of the total solid content in the emulsion.

The greatest feature of the present invention is the emulsion polymerization of unsaturated monomers that are sparingly soluble in water under conditions in which low-molecular-weight treated starch and a small amount of ethylenically unsaturated monomer that can be grafted with the JI powder coexist. As a result, the unsaturated monomer, which is poorly soluble in water, is indirectly acquired by the low-molecular-weight treated starch through a small amount of ethylenically unsaturated monomer that is easily grafted onto the starch, and it becomes an emulsifier. It is to fulfill the function of

Therefore, any type of unsaturated powder that is sparingly soluble in water can be used.

In addition, if an ethylenically unsaturated monomer that can be grafted onto low-molecular-weight starch is not present as a third component, the emulsion will remain uniform and stable. Emulsion polymerization of monomers can be carried out by conventionally known methods, such as radical polymerization using a d1 peroxide catalyst, redox reaction using a redox catalyst, and photostorm polymerization, whereby a stable naemulsion can be obtained. Can be done.

Since the emulsion obtained by the present invention has a water-soluble polymer grafted onto the water-soluble # powder image molecule decomposition product, it is possible to obtain a water-resistant film when it is formed, and also to be able to withstand strong acid or strong alkalinity. However, it has the characteristic of maintaining a stable emulsified state, and has much greater chemical stability than emulsions obtained by known methods using emulsifier '5r.

Furthermore, by controlling the degree of decomposition of the low-molecular-weight starch used, an emulsion of any viscosity can be obtained, and emulsions 17 suitable for each use can be easily produced.

Furthermore, since cheap starch is not used as a crude derivative of 1I31, an emulsion that is extremely advantageous in terms of bust can be obtained.

The emulsion Ia/l'i obtained by the method of the present invention can be used as a paint vehicle, as an adhesive for adhesives, paper, wood, inorganic materials, etc., and as a binder for coated paper, nonwoven fabrics, flocking, molding, etc. In addition, it can be used in a variety of ways, including as a sizing agent, mortar additive, and microbially degradable film.

Next, examples of the present invention will be shown.

Example 1 A solution prepared by dissolving 10 parts of acid-treated potato starch in a dish of 190 parts of water and 1 part of ethyl acrylate was placed in a reaction vessel, and to this was added 29 parts of styrene monomer and 30% peroxide as a catalyst. Add 1 part of 6 volumes of hydrogen water Q and 0.15 parts of ferrous ammonium sulfate, heat to 50°C with stirring, and continue the reaction at the same temperature for 6 hours to obtain a uniform milk I-shu solution. Ta.

This emulsion was placed in a sealed container and left at temperatures of 5° C. and 40° C. for half a year, but no particles were precipitated and no change in appearance was observed.

Further, when a part of this emulsion was dropped into 1N hydrochloric acid and 1N caustic soda aqueous solution, the particles were uniformly dispersed without breaking or agglomerating.

Example 2 190 parts by weight of water and 1 part by weight of 10 parts by weight of enzymatically decomposed waxy cornstarch dextrif were placed in a photopolymerization apparatus (internal irradiation method), and nitrogen substitution was performed for 15 minutes. Pre-irradiated for 5 minutes.

Next, styrene monomer RO, 1-its and acrylic acid monomer 2's 1s were added to this, and the mixture was heated at room temperature.
The emulsion thus obtained was placed in a sealed container and left open for half a year at temperatures of 5°C and 40°C.

During this time, changes in appearance were examined, but no phenomena such as precipitation or separation of particles were observed, and a uniform emulsion state was maintained.

Further, when a part of this emulsion was dropped into 1N hydrochloric acid and 1N caustic soda aqueous solution, the particles were uniformly dispersed without breaking or agglomerating.

EXAMPLE A bath solution prepared by dissolving 10 parts of commercially available dextrin (Joredux B-i 57, manufactured by Platman) in 190 parts by weight of gum water and 1 ml of acrylonitrile were placed in a reaction vessel, and 29 parts of styrene monomer was added to the reaction vessel. part and as a catalyst discerium ammonium nitrate I, MO
, 4 parts and 7 parts of 1N nitric acid were added, and the reaction was continued at 30° C. for 6 hours with stirring for 12 hours to obtain a uniform emulsion.

The particle diameter of this emulsion was measured using a transmission electron disintegration microscope, and the average diameter was 186 mμ in 100 measurements, and the emulsion had a smooth spherical shape with small dispersed particles.

(9) This emulsion was placed in a sealed container and left at temperatures of 5°C and 40°C for half a year, but no particles were precipitated and no change in appearance was observed.

Furthermore, when a portion of this emulsion was dropped into a 1N hydrochloric acid and 1N caustic soda water bath, the particles were uniformly dispersed without breaking or agglomerating.

Claims (1)

[Claims] (1) When low-molecular-weight treated starch and an ethylenically unsaturated monomer that can be grafted with the starch are combined in a toner to emulsion polymerize an unsaturated monomer that is sparingly soluble in water, the low-molecular-weight treated starch is 10~ of the same shape in the emulsion
50 weight l-%, /a powder and kraftable ethylenically unsaturated monomer in an amount of 0.5 to 5% of the total solid content in the emulsion.
Method for producing a soapless synthetic resin emulsion characterized in that it contains 1%