JP4007993B2 - Polymer emulsion and fiber treatment composition - Google Patents

Description

  The present invention relates to a polymer emulsion and a fiber / nonwoven fabric treatment composition using the polymer emulsion.

Water-based polymer emulsions are used in a wide range of fields such as civil engineering, architecture, automobiles, electricity, electronics, etc. by utilizing their characteristics in applications such as paints, adhesives and fiber treatment agents.
Important physical properties required for such applications include physical properties such as coating strength and adhesive strength. These strengths are not limited to those at room temperature, but are required to be strength at high temperatures, strength under high humidity, and strength under water immersion.
Furthermore, long-term durability such as weather resistance and holding power is often required. For example, when an aqueous polymer emulsion is used as a fiber treatment agent, one of the substrates is a nonwoven fabric. In general, non-woven fabric processed products (compositions) are widely used in filters, architecture, agriculture, sanitary fields, and the like. When used for these applications, a number of performances are required, but mechanical properties such as modulus and tensile strength during pulling are particularly important.

In particular, when used for roofing in the building field, a high modulus at a high temperature is required because an asphalt or resin impregnation step is performed during the processing. Methods for improving the mechanical performance of nonwoven fabrics used in such applications include resin-bonding methods using adhesives, thermal fusion methods, entanglement methods such as needle punching, and stitching methods such as stitch bonding. It is performed in one to several processing steps. Of these, the resin bond method is widely used alone or in combination with other methods because of its excellent tensile strength. As the binder for such a nonwoven fabric, a water-soluble resin, a styrene butadiene type, or an acrylic type emulsion is used.
Of these methods, the most commonly used method is a combined system of a melamine resin, which is a water-soluble resin, and a thermoplastic resin. Although this system has sufficient performance not only at room temperature but also at high temperatures, it has the disadvantage of lowering the working environment because it generates formalin in the drying / curing process. Although attempts have been made to improve the demerits by improving the formalin catcher and non-woven fabric processing line, in any case, there is no influence on the surroundings of formalin.

On the other hand, various attempts have been made to date even in a system that does not use a melamine resin. For example, Patent Document 1 discloses an example in which a specific crosslinkable monomer and a dicarboxylic acid are combined. However, the generation of a small amount of formalin cannot be suppressed due to the composition, and a non-woven fabric processed with a resin is used at a high temperature. The strength is not enough.
In addition, an example in which a crosslinkable monomer is introduced into a polymer and a polymer emulsion has a so-called soft core / hard shell structure is disclosed in Patent Document 2 and the like. The processed nonwoven fabric has insufficient strength at high temperatures. Conversely, an example of a hard core / soft shell structure with emphasis on film formability is disclosed in Patent Document 3, but this resin has good film formability and good physical properties at room temperature, but at high temperatures. The nonwoven fabric properties are not sufficient.

Moreover, although the combination of the high carboxylic acid latex and N-methylol acrylamide containing latex is disclosed by patent document 4, patent document 5, although this technique is favorable about the nonwoven fabric physical property at the time of high temperature contrary to the previous example, The physical properties at room temperature are not sufficient, formalin may be generated, and the viscosity is high compared to other resin systems, and the processability is insufficient.
In addition, water-based polymer emulsions are not only for the mechanical properties of the polymer itself or processed products using it, and adhesion to substrates such as fibers and nonwoven fabrics, but also for substrates such as asphalt, resin, concrete, mortar, paper, etc. Affinity for adhesives and work materials, and high and stable adhesive strength are also important.

Japanese Patent Laid-Open No. 3-74416 Japanese Patent Laid-Open No. 2-99656 Japanese Patent Application Laid-Open No. 6-298776 Japanese Patent Laid-Open No. 6-263391 JP-A-6-263807

  The problems to be solved by the present invention, as described above, are polymer emulsions that are excellent in physical properties and heat resistance, do not volatilize harmful substances such as formalin, and have no problems in workability and workability. Is to provide.

As a result of intensive studies on such problems, the present inventors have found that the following polymer emulsions can solve these problems, and have completed the present invention.
That is, the first of the present invention is a polymer emulsion obtained by a method including the following two steps: (1) 0.1 g to 10 mg equivalent of a carboxyl group and / or a hydroxyl group in 1 g of a solid component. And (2) having two or more glass transition temperatures in the range of 15 to 150 ° C., (3) a minimum film formation temperature of 5 ° C. or more and 5 ° C. or more lower than the highest glass transition temperature, (4 ) Toluene-insoluble content is 40 to 100%, the main component is at least one selected from (meth) acrylic acid ester monomers and aromatic radical polymerizable monomers, and a crosslinkable monomer. It is a polymer emulsion which consists of a component containing.
(I) 1 to 50% by weight of a crosslinkable monomer, 0.1 to 15% by weight of a polymerizable monomer having a carboxyl group and / or a hydroxyl group, and 35 to 98.9% by weight of other radical polymerizable monomers A step of emulsion polymerization of 80 to 50% by weight of a mixture containing 2% by weight.
(II) 0.5 to 60% by weight of a polymerizable monomer having a carboxyl group and / or a hydroxyl group, 1 to 30% by weight of a post-crosslinkable monomer, and other radically polymerizable monomers 10 to 98 Process for emulsion polymerization of 20 to 50% by weight of a mixture containing 5% by weight.

The second of the present invention is a fiber treatment composition comprising the polymer emulsion described in the first of the present invention.

The polymer emulsion of the present invention exhibits excellent mechanical properties when used in paints, adhesives, fiber treatment agents and the like.
Further, the nonwoven fabric treated with the composition of the present invention does not generate formalin as compared with the conventional one, and has a very high modulus at normal temperature and high temperature.

The inventors of the present invention have found that the emulsion can simultaneously exhibit good resin film-forming properties during nonwoven fabric processing and strength at room temperature / high temperature sufficient for resin-processed nonwoven fabrics.
The polymer latex in the present invention may have 0.1 to 10 milligram equivalent of a carboxyl group and / or a hydroxyl group to form a crosslinked structure together with a crosslinking monomer in order to exhibit sufficient heat resistance. desirable. If the amount of carboxyl group and / or hydroxyl group is less than this, the heat resistance cannot be fully exhibited, and the stability during polymerization is also lowered. On the other hand, when the amount is too large, the viscosity becomes too high, and the adhesiveness, the coating film-forming property, the impregnation into the nonwoven fabric and the room temperature performance are deteriorated. Desirably, it is 0.2-8 milligram equivalent, preferably 0.3-6 milligram equivalent, more preferably 0.35-5.2 milligram equivalent.

  Moreover, it is essential to have two or more glass transition temperatures within the range of 15 to 150 ° C. The highest Tg is required to be 5 ° C. or higher than MFT, preferably 18 ° C. or higher, and more preferably 20 ° C. or higher. The wider this difference, the better the balance between heat resistance and film formability. Further, the lower the MFT, the better the film formability. However, if the MFT is too low, the “hardness” of the resin composition formed is lowered. From this point, it is essential for MFT to be 5 ° C. or higher, preferably 10 to 50 ° C., more preferably 15 to 40 ° C.

In the present invention, it is desirable to form a strong coating film from the viewpoint of good physical properties. For this purpose, it is desirable that the toluene insoluble content is 40 to 100%, preferably 80 to 100%, more preferably 90 to 100%. When the toluene-insoluble content is below this range, the strength of the coating film particularly at high temperatures is lowered, which is not preferable. Next, the polymer emulsion in the present invention is polymerized in the following manner in the step (I).
It comprises 1 to 50% by weight of a crosslinkable monomer, 0.1 to 15% by weight of a polymerizable monomer having a carboxyl group and / or a hydroxyl group, and 35 to 98.9% by weight of another radical polymerizable monomer. Polymerization is performed in the step of emulsion polymerization of 95 to 10% by weight of the mixture. The amount of the crosslinkable monomer is preferably 1 to 30% by weight, more preferably 2 to 10% by weight. The amount of the carboxyl group and / or hydroxyl group is preferably considered to be a quantitative ratio capable of forming a crosslinked structure most efficiently with the amount of the crosslinkable monomer.

  The polymerization step (I) is a step of emulsion polymerization of 95 to 10% by weight of the mixture, preferably 80 to 30% by weight, more preferably 80 to 50% by weight. In the step (II) in the present invention, the polymerizable monomer having a carboxyl group and / or a hydroxyl group is 0.5 to 60% by weight, the post-crosslinkable monomer is 1 to 30% by weight, and other radical polymerizable properties. Polymerization is carried out in the step of emulsion polymerization of a mixture consisting of 10 to 98.5% by weight of monomer and 5 to 90% by weight. The amount of the polymerizable monomer having a carboxyl group and / or a hydroxyl group is preferably 5 to 30% by weight, more preferably 5 to 15% by weight.

The total amount of the polymerizable monomer mixture used in the polymerization step (I) and the polymerization step (II) is 100% by weight. Can be included. In the emulsion polymer of the present invention, the polymer produced in the polymerization step (I) (hereinafter referred to as polymer (I)) substantially forms the inner core of the polymer particles, and is produced in the polymerization step (II). It is preferable that the polymer to be formed (hereinafter referred to as polymer (II)) substantially forms an outer layer.
Here, “substantially forming the outer layer of the particles” does not necessarily need to completely cover the inner core material, and the film forming temperature of the particles substantially depends on the polymer (II). Means that In addition, “substantially forming the inner core” includes not only a case where a single spherical shape is formed and included, but also a case where it has several domain structures.

Although there is no restriction | limiting in particular in the order which implements polymerization process (I) and same (II) in this invention, It is preferable to consider and consider such a point and it implements in order of (I) and (II) normally. Is preferred. Moreover, the process of (I) and (II) should just be included in a polymerization system.
The polymer (I) preferably has a glass transition temperature measured by a differential thermal analyzer of 15 to 150 ° C, more preferably 15 to 100 ° C, more preferably 30.
~ 80 ° C.
The glass transition temperature of the polymer (II) is preferably lower than that of the polymer (I), and more preferably 5 ° C. or lower. The polymer (II) preferably has a glass transition temperature of 15 to 50 ° C, more preferably 15 to 40 ° C.

  The crosslinkable monomer used in the present invention is a compound having at least two radical polymerizable unsaturated bonds in the molecule. Examples include ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, ethylene glycol diacrylate, 1,3- Butylene glycol diacrylate, bis (4-acryloxypolyethoxyphenyl) propane, 1,5-pentanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate , Tetraethylene glycol diacrylate, other polyethylene glycol diacrylate, polypropylene glycol diacrylate, Printer-erythritol triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, allyl methacrylate, trivinylbenzene, triallyl isocyanurate. In addition, examples of the diene monomer include butadiene, chloroprene, and isoprene. The following post-crosslinkable monomers can also be used as the crosslinkable monomer.

  The polymerizable monomer having a carboxyl group used in the present invention is a monomer having a carboxyl group and a radical polymerizable unsaturated bond group. For example, at least one carboxyl group having 1 to 40 carbon atoms is mainly used. It is selected from one or more of those having one or more radically polymerizable unsaturated bond groups in the main chain or side chain at the α-position and / or β-position and subsequent positions. Acrylic acid, methacrylic acid, itaconic acid, citraconic acid, maleic acid, fumaric acid, vinyl benzoic acid, cinnamic acid and the like. Those having a polyvalent acid may be partially esterified.

Preferred examples of the polymerizable monomer having a carboxyl group include itaconic acid, fumaric acid, acrylic acid, methacrylic acid, and cinnamic acid.
The polymerizable monomer having a hydroxyl group in the present invention has a hydroxyl group and a radical polymerizable unsaturated bond group, and includes 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate. Acrylate, etc. These partially esterified products can also be used.
Examples of the polymerizable monomer having a preferred hydroxyl group are 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.
Examples of other radical polymerizable monomers used in the present invention include aromatic radical polymerizable monomers, acrylic acid esters, vinyl esters, vinyl ethers, vinyl cyanides, vinyl halides, olefins. And (after) amides having no crosslinkability, unsaturated acids, and basic monomers.

These polymerizable monomers may be used alone or in combination of two or more. The composition of these monomers greatly affects the glass transition temperature and minimum film forming temperature of the polymer produced. Also, styrene derivatives such as styrene and o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, vinylxylene, chlorostyrene, bromostyrene, vinylbenzyl chloride, p-tert-butylstyrene, acrylates or methacrylates Methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, n-amyl, isoamylhexyl, octyl, nonyl, decyl, dodecyl, octadecyl, cyclohexyl, Vinyl esters such as phenyl- and benzyl-acrylates or methacrylates, vinyl acetate, vinyl butyrate, vinyl stearate, vinyl laurate, vinyl myristate, vinyl propionate, vinyl versatate, As vinyl ethers, it may be mentioned, for example, methyl, ethyl, propyl, butyl, amyl, vinyl ethers having an alkyl group such as hexyl.

  Other examples include vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl halides such as vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene fluoride and vinylidene chloride, olefins such as ethylene, acrylamide, Amides without (post) crosslinkability such as methacrylamide, unsaturated acids such as vinyl sulfonic acid and styrene sulfonic acid, vinyl pyridine, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. Can be mentioned.

  Preferably, styrene and o-methyl styrene, m-methyl styrene, p-methyl styrene, vinyl xylene, chlorostyrene, bromostyrene, vinyl benzyl chloride, methyl acrylates as aromatic radical polymerizable monomers Radical polymerizable monomers selected from-, ethyl-, propyl-, n-butyl-, octyl-, nonyl-, octadecyl-, cyclohexyl-, phenyl-, benzyl-, as vinyl esters, vinyl acetate, vinyl butyrate Rate, vinyl stearate, vinyl laurate, vinyl versatate, etc., vinyl ethers, radically polymerizable monomers selected from methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, vinyl cyanides, acrylonitrile, As acrylonitrile, vinyl halides, vinyl chloride, vinyl bromide, vinylidene chloride, olefins, ethylene, propylene, (after) amides without crosslinkability, acrylamide, methacrylamide, vinyl as unsaturated acids Examples of the sulfonic acid, styrene sulfonic acid, and basic monomer include vinyl pyridine, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

  The post-crosslinkable monomer in the present invention refers to those capable of forming a crosslinked structure by reaction with other functional groups and those having self-crosslinkability. Examples include glycidyl compounds such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate, amides such as acrylamide and methacrylamide, N-methylol compounds and alkoxy compounds, vinyltrichlorosilane and vinyltriethoxy. Silicon-containing α, β-ethylenically unsaturated monomers such as silane are included.

  One or more of these post-crosslinkable monomers can be arbitrarily used. These post-crosslinkable monomers have a great influence on the glass transition temperature and film forming temperature of the polymer, the working environment characteristics, the performance when used for the final use, and the like. Preferred post-crosslinkable monomers are propylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, ethylene glycol diacrylate, 1,5-pentanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, Polypropylene glycol diacrylate, trimethylolpropane triacrylate, allyl methacrylate, trivinylbenzene, triallyl isocyanurate, butadiene, chloroprene, isoprene, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, acrylamide, methacrylamide, vinyltrichlorosilane And vinyltriethoxysilane.

Next, the emulsion polymerization method will be described in detail.
There is no restriction | limiting in particular in the method of emulsion polymerization, A conventionally well-known method is employable. That is, it is a method of emulsion polymerizing a polymerizable monomer in an aqueous dispersion medium by using a polymerization initiator in the presence of an emulsifier, a chain transfer agent, seed particles, other additives and the like as necessary. As a method for introducing a monomer (mixture) into the system, a conventionally known method can be adopted. A method of batch charging at an initial stage, a method of sequential addition, a rate of introduction and a monomer A method of changing the composition continuously or stepwise can be employed. Monomers (mixtures) may be used as they are, but those previously dispersed in an aqueous dispersion medium can also be used.

As the emulsifier, anionic, nonionic / nonionic anionic and cationic surfactants can be used.
Examples of the anionic surfactant include alkylbenzene sulfonic acid alkali metal salt, alkyldibenzene bissulfonic acid and its alkali metal salt, alkyl sulfate alkali metal salt, polyoxyethylene alkylphenol sulfate alkali metal salt, alkyl diphenyl ether disulfonate alkali Metal salts, alkali metal salts of dialkylsulfosuccinic acid and the like can be used.

As the nonionic surfactant, for example, polyoxyethylene alkylphenol ether, polyoxyethylene alkyl ether, polyoxyethylene higher fatty acid ester, ethylene oxide-propylene oxide block copolymer and the like can be used. In addition to these, reactive surfactants can also be used.
The reactive surfactant has a radical polymerizable functional group in one molecule and has one or more functional machines selected from a sulfonic acid group, a sulfonic acid ester group, and a sulfonic acid group, or in one molecule. Those having a radical polymerizable functional group and having polyoxyethylene, polyoxypropylene, polyoxyethylene polyoxypropylene composite type alkyl ether or alcohol, and the like.

  An acrylic water-soluble oligomer may be used in combination with the anionic surfactant. Furthermore, a water-soluble polymer compound having an action as a colloid protective agent such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose and the like can be used as necessary. Since these surfactants and water-soluble polymer compounds may decrease the water resistance of the resulting polymer as the amount used increases, the amount used is preferably smaller, but at least the polymerization stability and It is preferable to use the minimum amount necessary for maintaining the mechanical stability and chemical stability of the product. The amount used is usually selected in the range of 0.1 to 7 parts by weight per 100 parts by weight of the monomer.

  Also preferably, anion, nonionic anionic (reactive) emulsifier, organic and inorganic phosphoric acid, titanium and silica, silane, silicone, tackifier, petroleum resin, animal and vegetable oils, skin, hair and other esters, hydrates , Colloid, and the stability of the crosslinkable monomer and the polymerizable monomer having a carboxyl group and / or a hydroxyl group in the present invention during the polymerization, and further, two kinds according to the present invention. This is particularly effective for stability when blending the above polymer emulsion and for maintaining the performance thereafter. More preferably, an anionic, nonionic anionic (reactive) emulsifier, organic and inorganic phosphoric acid ester are used.

There is no restriction | limiting in particular as a chain transfer agent, It can select suitably from what is conventionally used for the molecular weight adjustment of a normal polymerization reaction, and can be used. Examples of such chain transfer agents include mercaptans having an alkyl group having 1 to 30 carbon atoms such as propyl mercaptan, butyl mercaptan, dodecyl mercaptan, octyl thioglycolate, thioglycolic acid, and diphenylsulfide. Organic sulfur compounds having 1 to 30 carbon atoms, halogenated hydrocarbons having 1 to 20 carbon atoms such as carbon tetrachloride, carbon tetrabromide and bromotrichloromethane, and non-organic compounds such as α-methylstyrene dimer. Hydrocarbons having a saturated group are included.
These chain transfer agents may be used alone or in combination of two or more. Such a chain transfer agent employs a method in which it is mixed with a monomer, a method in which it is initially charged all at once, a method in which it is sequentially added, a method in which the introduction rate and its composition are changed continuously or stepwise, etc. be able to.

As the polymerization initiator, a compound that generates radicals at a temperature of about 0 to 150 ° C. is used. As this polymerization initiator, a water-soluble one is mainly used, but an oil-soluble one may also be used.
Typical polymerization initiators include water-soluble persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate, inorganic peroxides such as hydrogen peroxide, benzoyl peroxide, cumene hydroperoxide, lauroyl peroxide, Examples thereof include organic peroxides such as tertiary butyl peroxide and tertiary butyl peroxy-2-ethylhexanoate, and azo compounds such as azobisisobutyronitrile. In addition, a so-called redox initiator that combines the above peroxide and a reducing agent and generates a radical in the presence of a small amount of metal ions as necessary is also used.
Examples of this redox system include hydrogen peroxide-ferrous chloride system, cumene hydroperoxide-sodium ascorbate system, and the like.
Furthermore, an initiator having an amino group such as azobisisobutylamine can also be used. The amount of these polymerization initiators is usually selected in the range of 0.1 to 2.5 parts by weight with respect to 100 parts by weight of the total amount of monomers. Moreover, the said peroxide may be used 1 type and may be used in combination of 2 or more type.

The polymerization reaction is usually performed at a temperature in the range of 0 to 130 ° C, preferably 30 to 100 ° C. There is no restriction | limiting in particular in superposition | polymerization time, Usually, 1 to 24 hours, Preferably it is 1 to 10 hours.
Although there is no restriction | limiting in particular in the particle diameter of the polymer emulsion in this invention, It is 100-3000 nm, Preferably it is 20-800 nm, More preferably, it is 10-500 nm. Moreover, although there is no restriction | limiting in particular also in solid content, it is 10 to 75 weight%, Preferably it is 20 to 65 weight%, More preferably, it is 30 to 60 weight%.

In addition, solid content in this invention is defined as a weight ratio with respect to before drying at the time of drying a polymer emulsion and a composition with the drying method mentioned later. The glass transition temperature (Tg) in the present invention is defined in this case as an inflection point of a change in calorific value when a polymer emulsion and a dried product of the composition are subjected to temperature rise measurement using a differential scanning calorimeter (DSC). . A specific measurement method will be described later.
Also, the minimum film formation temperature (MFT) in the present invention means that a liquid to be measured is uniformly applied with a width of 1 cm and a thickness of 0.2 mm on a temperature gradient tester, and then the liquid is not directly blown. It is defined as the lowest temperature at which the liquid dries naturally and forms a continuous film. Further, the toluene insoluble content is defined as the weight ratio of the toluene insoluble matter after the thin film-like dry matter of the polymer emulsion is immersed in toluene to the dry matter before immersion. A specific measurement method will be described later.

Next, the present invention relates to a fiber treatment composition comprising the copolymer emulsion.
As this composition, the polymer emulsion may be used as it is, or two or more emulsions having different compositions may be used. The latter mixing method is not particularly limited, and it may be at the time of preparing the emulsion or at the time of fiber treatment, but preferably after emulsion polymerization. In this case, the composition and properties of the emulsion to be mixed may be within the scope of the present invention, but preferably the amount of the monomer having a carboxyl group and / or a hydroxyl group and / or the amount of the post-crosslinkable monomer and the particle size. Are combinations of different emulsions. More preferred is a combination of a monomer having a carboxyl group and / or a hydroxyl group with a large amount and a particle size of less than 300 nm, and a post-crosslinkable monomer having a large amount and a particle size of less than 600 nm. More preferably, an emulsion into which a monomer having two or more functional groups of a monomer having a carboxyl group and / or a hydroxyl group is introduced is used.

This fiber processing composition can further improve performance by using a crosslinking agent in combination.
The cross-linking agent referred to in the present invention refers to a substance having two or more functional groups capable of reacting with a carboxyl group and / or a hydroxyl group introduced into a polymer.
If these are illustrated, an aziridine compound having two or more ethyleneimine groups, an epoxy compound having two or more epoxy groups, a carbodiimide compound having two or more carbodiimide groups, a compound having two or more oxazoline groups Zinc, titanium, silica, alumina, silane, silicone, lithium and other metal (oxidation, aquo, ammonium, carbonic acid, isocyanate, carboxyl, glycidyl) salts, and the like. These cross-linking agents are usually used in the range of 0.05 to 40 parts by weight, preferably 0.1 to 30 parts by weight, and more preferably 0.00 to 100 parts by weight of the emulsion polymer described above. 5 to 30 parts by weight. These crosslinking agents can be used in combination with one or more compounds.

Moreover, performance can be improved dramatically by using a crosslinking accelerator. The term “crosslinking accelerator” as used herein refers to a substance having two or more functional groups capable of reacting with a carboxyl group and / or hydroxyl group introduced into a polymer or with a carboxyl group and / or hydroxyl group introduced into a polymer. A substance that promotes the reaction. For example, inorganic salts such as amines, amides, phosphorus, zinc, silica, titanium, and derivatives thereof.
It may be preferred if the composition contains a water-soluble polymer. Examples of these include (co) polymers having a carboxyl group, polyvinyl alcohol, natural water-soluble polymers, and the like. Various additives may be added to the composition in addition to the polymer emulsion and the crosslinking agent. Specific examples of these include antiseptics, bactericides, viscosity modifiers, pH adjusters, antifoaming agents, plasticizers, wetting agents, foaming agents, and the like.

The polymer emulsion and the resin composition thus produced can be used for fiber processing of conventionally known materials, forms, or applications.
Examples of materials include polyester, polypropylene, polyurethane, polyethylene, polyvinyl chloride, carbon, acrylic, acetate, (aromatic) polyamide, rayon, copper ammonia, nylon, acrylic, polyvinyl alcohol, vinylidene, polyacetal and other synthetic fibers, glass And inorganic fibers such as ceramic and silicon carbide, natural fibers such as wool, cotton and hemp, and pulp.

In terms of form, for example, knitted fabric, woven fabric, non-woven fabric, synthetic paper, and the like can be used without limitation. Moreover, it can apply to the fiber used by the example as described below also from an application. For example, filters, interior / exterior materials for buildings, interior materials for automobiles, house curtains and seedling sheets for agriculture, medical gowns and masks, sheets, clothing interlinings, sanitary goods, and decorative paper for paper it can. In particular, the present invention is very effective as a binder for roofing nonwoven fabric that requires heat resistance in order to undergo asphalt impregnation processing in addition to tensile / tear performance.
These fibers are impregnated with a resin by, for example, an impregnation method, a spray method, and the like, dried, and then heat-cured as necessary to perform resin processing of the fibers for use in the intended purpose (resin Processing) Obtain fiber. The solid content and viscosity of the composition are appropriately determined depending on the difference in the processing methods.

Hereinafter, the present invention will be described more specifically with reference to examples. In the text, parts indicate parts by weight, and% indicates% by weight. In the following examples, solid content, glass transition temperature, minimum film forming temperature, and particle size were measured by the following methods.
(I) Solid content 0.5-1.0g of polymer emulsion or a composition is precisely weighed on an aluminum dish, and it is made to stand on 105 degreeC on the conditions for 3 hours, and is dried. The weight percentage of the heating residue after drying relative to the weight before drying was defined as the solid content.
(B) Glass transition temperature (Tg)
After drying the composition at 105 ° C. for 3 hours, an appropriate amount of dry matter is measured using a differential scanning calorimeter (DSC).
The measurement was performed at a heating rate of 10 ° C./min, and the inflection point of the change in calorie was defined as Tg.

(C) Minimum film formation temperature (MFT)
After the liquid to be measured on the temperature gradient tester is uniformly applied with a width of 1 cm and a thickness of 0.2 mm, the liquid is allowed to stand so that no direct wind is applied to the liquid, and the liquid is dried to form a continuous film. The minimum temperature was MFT.
(D) Toluene-insoluble content A polymer emulsion whose pH is adjusted to 7 by dropwise addition of 15% sodium hydroxide solution is thinly applied to a release paper and sufficiently dried at 105 ° C. Cut into a size (length 10 cm × width 10 cm × thickness 100 μm), dipped in 300 g of toluene and left at 20 ° C. for 2 days. Thereafter, the toluene solution is filtered through a 200-mesh stainless mesh, and the insoluble coating film is taken out and sufficiently dried at 150 ° C. for 3 hours. Toluene insoluble matter is defined as the value of the ratio of the weight of the coating film after immersion in toluene to the weight before immersion.
(E) Particle diameter It measured using the particle diameter measuring device using the light-scattering method.

(F) Shrinkage rate As a polyester nonwoven fabric, a polyethylene terephthalate nonwoven fabric having a basis weight of 100 g / m ² is used as a raw fabric. The polymer emulsion obtained according to the present invention is applied to this polyester nonwoven fabric, and the amount of resin after drying is measured as the raw fabric. After impregnating with a target of 25% of the applied amount, a drying process of 110 ° C. (5 minutes) + 180 ° C. (3 minutes) and a resin curing process are performed to obtain a measurement sample.
A measurement sample is dried at 50 ° C. for 3 days, and then cut into a size of 50 cm in length and 30 cm in width. However, the direction parallel to the production line of the measurement sample is vertical and the direction vertical is horizontal. Using two iron plates of length 40cm x width 2cm x thickness 0.5cm so that the upper and lower ends in the vertical direction of the sample are not deformed, the sample is sandwiched from both sides and pressed with a small vise. Then, hold the top end as it is, immerse it in salad oil kept at 220 ° C. for 1 second and immediately pull it up. The rate of change of the length after immersion in the horizontal direction of the pulled-up sample with respect to the length before immersion is defined as the contraction rate, and the sign when contracted is positive.

[Example 1]
809 parts of water is put into a glass reaction vessel. Next, 385 parts of methyl methacrylate, 117 parts of n-butyl acrylate, 11 parts of methacrylic acid, 27 parts of glycidyl methacrylate, sodium polyoxyethylene alkylphenyl ether sulfate (trade name Lebenol WZ, manufactured by Kao Corporation) 0.5 part (solid Equivalent to a mold part), sodium alkylphenyl ether sulfate (trade name Neoperex F25, manufactured by Kao Corporation), 4 parts, 0.97 parts of ammonium persulfate, and 180 parts of water are mixed uniformly using an emulsifier and emulsified. To prepare an emulsion (AI).
While maintaining the reaction vessel at 78 ° C., the emulsion (AI) was gradually added dropwise over 120 minutes to cause the reaction. After completion of the reaction, this time 190 parts of methyl methacrylate, 116 parts of n-butyl acrylate, 36 parts of methacrylic acid, 18 parts of glycidyl methacrylate, 1 part of sodium polyoxyethylene alkylphenyl ether sulfate, 1.5 parts of sodium alkylphenyl ether sulfate, An emulsion (AII) is prepared by mixing and emulsifying 1.00 parts of ammonium sulfate and 100 parts of water using an emulsifier, and this liquid is dropped into the reaction vessel over 90 minutes.

After completion of the reaction, the reaction vessel was cooled, and then a 15% sodium hydroxide solution was added dropwise to adjust the pH to 7. Thus, a polymer emulsion A-1 was obtained. The solid content was 45%, and two observed Tgs were 43 ° C and 63 ° C. The MFT was 41 ° C., the particle size was 190 nm, and the toluene insoluble content was 94.5 wt%. In the evaluation of this polymer, a polyethylene terephthalate nonwoven fabric having a basis weight of 100 g / m ² was used as a raw material for the polyester nonwoven fabric. After impregnating the above polymer emulsion A-1 into this polyester nonwoven fabric with a target of 25% of the weight of the original fabric, the drying treatment and resin at 110 ° C. for 5 minutes + 180 ° C. for 3 minutes The evaluation processing resin processing nonwoven fabric sample was obtained.
When the samples were evaluated according to the method of JIS-A-6022, the average of the warp direction and the horizontal direction of the non-woven fabric was 21 kg / 5 cm at 3% elongation in the normal tensile strength, 45 kg / 5 cm at break strength, and elongation at break. The degree was 50%. Further, the tear strength was 10.6 kg, which was a good performance with almost no deterioration in strength compared to the case where the resin was not processed. When this sample was dipped in a salad oil kept at 220 ° C. for 1 second and pulled up, the nonwoven fabric showed a very good performance with a shrinkage ratio of 1.3% in the horizontal direction.

[Example 2]
100 parts of polymer emulsion A-1 prepared in Example 1 and aziridine (diphenylmethane-bis-4, 4′-N, N′-diethyleneurea, manufactured by Meisei Chemical Industry Co., Ltd., trade name FS-50) 20 The parts were mixed and stirred until uniform to obtain a nonwoven fabric binder composition X-1.
The nonwoven fabric was processed in the same manner as in Example 1, and the physical properties were measured. As a result, the strength at 3% elongation in the normal tensile strength was 25 kg / 5 cm, the breaking strength was 47 kg / 5 cm, and the breaking elongation was 47%. Although the tear strength was slightly reduced when the resin was not processed, it was at a level causing no practical problem.
Further, when this sample was dipped in high-temperature salad oil in the same manner as described above, the nonwoven fabric showed a very good performance with a shrinkage ratio of 0.9% in the horizontal direction.

[Examples 3 to 10]
The composition was changed as shown in Table 1 to prepare a polymer emulsion or composition. The emulsifier species / amount in each Example was the same as that in Example 1 for Examples 4, 7, 8, 9, and 10.
However, for Example 3, 10.8 parts of polyoxyethylene nonylphenyl ether (trade name Emulgen 950, manufactured by Kao Corporation) having a different HLB value was newly added to the emulsion (AII). Emulsified (AII2) was prepared and used.
Further, the amount of the emulsifier in Examples 5 and 6 was adjusted to a concentration proportional to the monomer amount ratio of I and II and added. About the preparation method, each polymer emulsion was produced by the method similar to Example 1. FIG.
These latexes were processed into nonwoven fabrics in the same manner as in Example 1 to obtain resin processed nonwoven fabric samples for evaluation. When the sample was evaluated according to the method of JIS A6022, as shown in Table 5, the tensile performance and the shrinkage rate were both good, the film forming property of the resin was good, and the resin performance could be sufficiently expressed. Below, the tear performance was also good.

[Example 11]
809 parts of water is put into a glass reaction vessel.
Next, 472.5 parts of butyl methacrylate, 121.5 parts of n-butyl acrylate, 13.5 parts of acrylic acid, 54 parts of glycidyl methacrylate, 13.5 parts of divinylbenzene, 0.5 part of polyoxyethylene alkylphenyl ether sodium sulfate, 4 parts of sodium alkylphenyl ether sulfate, 0.97 part of ammonium persulfate and 220 parts of water are uniformly mixed using an emulsifier and emulsified to prepare an emulsion (AI2).
While maintaining the reaction vessel at 88 ° C., the emulsion (AI2) was gradually added dropwise over 240 minutes to cause the reaction. After completion of the reaction, this time 108 parts of butyl methacrylate, 72 parts of n-butyl acrylate, 18 parts of acrylic acid, 9 parts of divinylbenzene, 18 parts of glycidyl methacrylate, 1 part of sodium polyoxyethylene alkylphenyl ether sulfate, 1 part of sodium alkylphenyl ether sulfate .5 parts, 1.00 parts of ammonium persulfate and 60 parts of water are mixed and emulsified using an emulsifier to prepare an emulsion (AII3), and this liquid is dropped into the reaction vessel over 240 minutes.

  After completion of the reaction, the reaction vessel was cooled, and then a 15% sodium hydroxide solution was added dropwise to adjust the pH to 7. Thus, a polymer emulsion A-11 was obtained. The solid content was 45%, and two observed Tgs were 43 ° C and 63 ° C. The MFT was 41 ° C., the particle size was 240 nm, and the toluene insoluble content was 92 wt%. Further, when the nonwoven fabric was processed in the same manner as in Example 1 and the physical properties were measured, the normal tensile strength was 21 kg / 5 cm at 3% elongation, 45 kg / 5 cm at break strength, and 50% at break elongation. there were. Further, the tear strength was 10.6 kg, which was a good performance with almost no decrease in strength compared to the case where the resin was not processed. When this sample was dipped in a salad oil kept at 220 ° C. for 1 second and pulled up, the nonwoven fabric showed a very good performance with a shrinkage ratio of 1.3% in the horizontal direction.

[Examples 12 and 13]
100 parts of the polymer emulsion A-11 prepared in Example 11 and in Example 12, aziridine (diphenylmethane-bis-4, 4′-N, N′-diethyleneurea, manufactured by Meisei Chemical Industry Co., Ltd., trade name) FS-50), in Example 13, epoxy (sorbitol epoxy, manufactured by Dainippon Ink Co., Ltd., trade name CR-5L), 20 parts of each were mixed and stirred until uniform, binder composition X for nonwoven fabric -2, X-3 was obtained.
The nonwoven fabric was processed in the same manner as in Example 1, and the physical properties were measured. In normal tensile strength, X-2 had a strength at 3% elongation of 25 kg / 5 cm, a breaking strength of 47 kg / 5 cm, and a breaking elongation. 47% and X-3 had a strength at 3% elongation of 24 kg / 5 cm, a breaking strength of 46 kg / 5 cm, and a breaking elongation of 47%. Although the tear strength was slightly reduced when the resin was not processed, it was at a level causing no practical problem. Also, when this sample was dipped in high temperature salad oil as before, the shrinkage ratio of the nonwoven fabric was 0.9% for X-2 and 1.1% for X-3, showing very good performance. It was.

[Examples 14 to 46 , Reference Examples 16 to 18, Reference Example 36 ]
The compositions were changed as shown in Tables 2 to 5 to prepare polymer emulsions or compositions.
The initiator and emulsifier species in each example were the same type as in Example 1,
The amount was adjusted to a concentration proportional to the monomer ratio and added.
About the preparation method, each polymer emulsion was produced by the method similar to Example 1. FIG. Using these latexes, the nonwoven fabric was treated in the same manner as in Example 1 to obtain a resin processed nonwoven fabric sample for evaluation.
When the samples were evaluated according to the method of JIS-A-6022, as shown in Tables 9 to 12, both the tensile performance and the shrinkage ratio were good, the resin film formability was good, and the resin performance was good. Under the conditions that can be fully expressed, the tearing performance was also good.

[Examples 47 to 54]
The composition was changed as shown in Table 6, and a polymer emulsion was mixed and adjusted. These latex mixtures were processed into nonwoven fabrics in the same manner as in Example 1 to obtain resin processed nonwoven fabric samples for evaluation.
When the sample was evaluated according to the method of JIS-A-6022, as shown in Table 12, both the tensile performance and the shrinkage ratio were good, the resin film formability was good, and the resin performance was sufficient. Under the circumstances where it can be developed, the tear performance was also good.

[Comparative Example 1]
While maintaining the reaction vessel at 78 ° C., 680 g of water is charged into the glass reaction vessel.
Next, 641.7 parts of methyl methacrylate, 195 parts of n-butyl acrylate, 18.3 parts of methacrylic acid, 45 parts of glycidyl methacrylate, 0.8 part of sodium polyoxyethylene alkylphenyl ether sulfate, 6 parts of sodium alkylphenyl ether sulfate, 1.52 parts of ammonium sulfate and 282 parts of water are uniformly mixed using an emulsifier and emulsified to prepare an emulsion (BI). While maintaining the reaction vessel at 78 ° C., the emulsion (BI) was gradually added dropwise over 120 minutes to cause the reaction. After completion of the reaction, the reaction vessel was cooled, and then a 15% sodium hydroxide solution was added dropwise to adjust the pH to 7. Thus, a polymer emulsion B-1 was obtained. The solid content was 45% and Tg was only observed at 63 ° C. The MFT was 61 ° C., the particle size was 190 nm, and the toluene insoluble content was 97.5 wt%.

  The emulsion B-1 was used to process the nonwoven fabric in the same manner as in Example 1 and the physical properties were measured. In normal tensile strength, the stress at 3% elongation was 12 kg / 5 cm, the breaking strength was 45 kg / 5 cm, the elongation at break The degree was 60%. Moreover, when this sample was immersed in 220 degreeC salad oil, the shrinkage | contraction rate was 3.5% in the horizontal direction of the nonwoven fabric, and it came out of the range which can be used practically. Moreover, when the cross section of the nonwoven fabric immediately after this process was observed, many cracks generate | occur | produced in adhering resin and it turned out that film-forming property is low. The tear strength also showed good performance with almost no decrease in strength compared to the case where the resin was not processed, but this was presumably because the film-forming property was rather low and the performance of the resin was not fully expressed. Is done. The results are summarized in Table 13.

[Comparative Example 2]
With respect to 100 parts of the polymer emulsion B-1 prepared in Comparative Example 1, 20 parts of aziridine were mixed and stirred until uniform, to obtain a nonwoven fabric binder composition Y-1.
The nonwoven fabric was processed in the same manner as in Example 1 and the physical properties were measured. As a result, the tensile strength at 15% elongation was 15 kg / 5 cm, the breaking strength was 43 kg / 5 cm, and the elongation at break was 58%. .
Moreover, when this sample was immersed in 220 degreeC salad oil, the shrinkage | contraction rate was 2.5% in the horizontal direction of the nonwoven fabric, and it could not be said that it was favorable. Moreover, when the cross section of the nonwoven fabric immediately after this process was observed, many cracks generate | occur | produced in resin which adhered, and it turned out that this composition is also low in film forming property.

[Comparative Example 3]
While maintaining the reaction vessel at 78 ° C., 680 g of water is charged into the glass reaction vessel in the same manner as in Example 1.
Next, 475 parts of methyl methacrylate, 290 parts of n-butyl acrylate, 90 parts of methacrylic acid, 45 parts of glycidyl methacrylate, 2 parts of sodium polyoxyethylene alkylphenyl ether sulfate, 3 parts of sodium alkylphenyl ether sulfate, 2.00 parts of ammonium persulfate, 200 parts of water is mixed using an emulsifier and emulsified to prepare an emulsion (BII2), and this liquid is dropped into the reaction vessel over 120 minutes. After completion of the reaction, the reaction vessel was cooled, and then a 15% sodium hydroxide solution was added dropwise to adjust the pH to 7. Thus, a polymer emulsion B-3 was obtained. The solid content was 43%, and Tg was observed only at 43 ° C. The MFT was 41 ° C., the particle size was 189 nm, and the toluene insoluble content was 95.1 wt%.

The nonwoven fabric was processed and the physical properties were measured in the same manner as in Example 1. The normal tensile strength was 15 kg / 5 cm at 3% elongation, 46 kg / 5 cm at break strength, and 55% at break when stretched at 3%. . Moreover, when this sample was immersed in 220 degreeC salad oil, the shrinkage | contraction rate was 4.0% in the horizontal direction of the nonwoven fabric, and it could not be said that it was favorable. However, the cross section of the nonwoven fabric immediately after the processing was observed, but no abnormality was observed in the adhered resin, and no problem was found in film formability.

[Comparative Examples 4 to 7]
The composition was changed as shown in Table 7 to prepare a polymer emulsion or composition. The initiator and the emulsifier species in each comparative example were the same as those in Example 1, and the amount thereof was adjusted to a concentration proportional to the monomer ratio and added. About the preparation method, each polymer emulsion was produced by the method similar to Example 1. FIG.
Although the tensile performance is at a practical level, there is no problem in film formability and the tear performance is also good, but the shrinkage rate is out of the practical level, from the viewpoint of heat resistance. Did not show sufficient performance.

[Comparative Example 8]
While maintaining the reaction vessel at 78 ° C., 680 g of water is charged into the glass reaction vessel. Next, 657 parts of butyl methacrylate, 162 parts of n-butyl acrylate, 18 parts of acrylic acid, 45 parts of glycidyl methacrylate, 18 parts of divinylbenzene, 0.8 part of sodium polyoxyethylene alkylphenyl ether sulfate, 6 parts of sodium alkylphenyl ether sulfate, 1.52 parts of ammonium persulfate and 282 parts of water are uniformly mixed using an emulsifier and emulsified to prepare an emulsion (BI2).
While maintaining the reaction vessel at 78 ° C., the emulsion (BI2) was gradually added dropwise over 480 minutes to cause the reaction. After the completion of the reaction, the reaction vessel was cooled, and 15% sodium hydroxide solution was added dropwise to adjust the pH to 7. Thus, a polymer emulsion B-8 was obtained. The solid content was 45% and Tg was only observed at 63 ° C. The MFT was 61 ° C., the particle size was 260 nm, and the toluene insoluble content was 93.5 wt%.

  The nonwoven fabric was processed in the same manner as in Example 1 and the physical properties were measured. As a result, in the normal tensile strength, the stress at 3% elongation was 12 kg / 5 cm, the breaking strength was 45 kg / 5 cm, and the breaking elongation was 46%. . Moreover, when this sample was immersed in 220 degreeC salad oil, the shrinkage | contraction rate was 3.5% in the horizontal direction of the nonwoven fabric, and it came out of the range which can be used practically. Moreover, when the cross section of the nonwoven fabric immediately after this process was observed, many cracks generate | occur | produced in adhering resin and it turned out that film-forming property is low. The tear strength was 11.2 kg, which was a good performance with almost no decrease in strength compared to the case where the resin was not processed, but this was rather low in film formability and the resin performance was fully expressed. It is guessed that it is not.

[Comparative Example 9]
100 parts of the polymer emulsion B-8 prepared in Comparative Example 8 was mixed with 20 parts of aziridine and stirred until uniform, to obtain a nonwoven fabric binder composition Y-2. The nonwoven fabric was processed in the same manner as in Example 1 and the physical properties were measured. The normal tensile strength was 15 kg / 5 cm at 3% elongation, 43 kg / 5 cm at break strength, and 38% at break elongation. . Moreover, when this sample was immersed in 220 degreeC salad oil, the shrinkage | contraction rate was 2.5% in the horizontal direction of the nonwoven fabric, and it could not be said that it was favorable.
Moreover, when the cross section of the nonwoven fabric immediately after this process was observed, many cracks generate | occur | produced in resin which adhered, and it turned out that this composition is also low in film forming property.

[Comparative Example 10]
While maintaining the reaction vessel at 78 ° C., 680 g of water is charged into the glass reaction vessel in the same manner as in Example 1.
Next, 585 parts of butyl methacrylate, 162 parts of n-butyl acrylate, 90 parts of acrylic acid, 18 parts of divinylbenzene, 45 parts of glycidyl methacrylate, 2 parts of sodium polyoxyethylene alkylphenyl ether sulfate, 3 parts of polyoxyethylene nonylphenyl ether, 2.00 parts of ammonium sulfate and 200 parts of water are mixed and emulsified using an emulsifier to prepare an emulsion (BII3), and this liquid is dropped into the reaction vessel over 120 minutes. After completion of the reaction, the reaction vessel was cooled, and then a 15% sodium hydroxide solution was added dropwise to adjust the pH to 7. Thus, a polymer emulsion B-10 was obtained. The solid content was 43%, and Tg was observed only at 43 ° C. The MFT was 41 ° C., the particle size was 189 nm, and the toluene insoluble content was 95.1 wt%.

  The nonwoven fabric was processed in the same manner as in Example 1 and the physical properties were measured. As a result, the tensile strength at 15% elongation was 15 kg / 5 cm, the breaking strength was 46 kg / 5 cm, and the breaking elongation was 60%. . Moreover, when this sample was immersed in 220 degreeC salad oil, the shrinkage | contraction rate was 4.0% in the horizontal direction of the nonwoven fabric, and it could not be said that it was favorable. However, the cross section of the nonwoven fabric immediately after the processing was observed, but no abnormality was observed in the adhered resin, and no problem was found in film formability.

[Comparative Examples 11-15]
The composition was changed as shown in Table 8 to prepare a polymer emulsion or composition. In each comparative example, the same initiator and emulsifier species were used as in Example 1, and the amount thereof was added in proportion to the monomer ratio. About the preparation method, each polymer emulsion was produced by the method similar to Example 1. FIG.
Although the tensile performance is at a practical level, there is no problem in film formability and the tear performance is also good, but the shrinkage rate is out of the practical level, from the viewpoint of heat resistance. Did not show sufficient performance.

[Comparative Examples 16 to 18]
The composition was changed as shown in Table 8, and the polymer emulsion was mixed and adjusted. Although the tensile performance is at a practical level, there is no problem in film formability and the tear performance is also good, but the shrinkage rate is out of the practical level, from the viewpoint of heat resistance. Did not show sufficient performance.

The polymer emulsion of the present invention can be used in fields such as paints, adhesives and fiber treatment agents. Further, the nonwoven fabric treated with the composition of the present invention does not generate formalin as compared with the conventional one, and has a very high modulus at normal temperature and high temperature.

Claims (8)

A polymer emulsion obtained by a method comprising the following two steps: (1) 0.1 g to 10 mg equivalent of a carboxyl group and / or a hydroxyl group in 1 g of a solid component, and (2) 15 to It has two or more glass transition temperatures in the range of 150 ° C., (3) the lowest film formation temperature is 5 ° C. or more and 5 ° C. lower than the highest glass transition temperature, and (4) toluene insoluble content is 40 to 100 %, A polymer emulsion comprising a component containing at least one selected from a (meth) acrylic acid ester monomer and an aromatic radical polymerizable monomer as a main component and a crosslinkable monomer .
(I) 1 to 50% by weight of a crosslinkable monomer, 0.1 to 15% by weight of a polymerizable monomer having a carboxyl group and / or a hydroxyl group, and 35 to 98.9% by weight of other radical polymerizable monomers A step of emulsion polymerization of 80 to 50% by weight of a mixture containing 2% by weight.
(II) 0.5 to 60% by weight of a polymerizable monomer having a carboxyl group and / or a hydroxyl group, 1 to 30% by weight of a post-crosslinkable monomer, and other radically polymerizable monomers 10 to 98 Process for emulsion polymerization of 20 to 50% by weight of a mixture containing 5% by weight.   The polymer emulsion according to claim 1, which has a carboxyl group and / or a hydroxyl group in an amount of 0.2 to 8 milligram equivalent in 1 g of solid content. The polymer emulsion according to claim 1 or 2 , wherein the minimum film forming temperature is 10 to 50 ° C. The polymer emulsion according to any one of claims 1 to 3 , wherein the highest glass transition temperature is 18 ° C or more higher than the lowest film formation temperature. The polymer emulsion according to any one of claims 1 to 4 , having a toluene insoluble content of 80 to 100%. The polymer emulsion according to claim 1 , wherein the crosslinkable monomer is 1 to 30% by weight in the polymerization step (I). The polymer emulsion according to claim 1 , wherein the polymerizable monomer having a carboxyl group and / or a hydroxyl group is 5 to 30% by weight in the polymerization step (II). (After) the crosslinkable monomer is glycidyl methacrylate, trimethylolpropane triacrylate, polymer emulsion according to claim 7 is a least one selected from divinylbenzene.