JP2827624B2 - Method for producing reactive microgel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a reactive microgel having a functional group such as a polymerizable double bond or a hydroxyl group. The present invention relates to a method for producing a reactive microgel useful as a highly sensitive resist material, a binder for paints and printing inks, and also as a reactive filler.

[0002]

2. Description of the Related Art Microgels are crosslinked polymer particles having a size such as a colloid, for example, a diameter of 0.001 to 10 .mu.m, generally 1 .mu.m or less. Is a new polymer material. However, those with no reactive groups on the surface of the microgel serve only as a filler,
It was only used for the purpose of improving the strength of the material. Reactive microgels having reactive groups on the surface of the microgel were published in 1975 by Funke, Germany. The microgels synthesized by Funke are emulsion polymerized under very mild conditions with monomers having two or more polymerizable double bonds, and the polymerizable double bonds remaining without reacting on the surface are modified with other reagents. However, it was converted into various reactive groups. As an example, a method has been proposed in which a peroxide is used to convert to an epoxy group, borane is used to convert to a hydroxyl group, hydrogen halide is used to convert to a halogen group, and ozone is used to convert to a carboxyl group. However, since all of these reactions do not take place in a system in which water is present, the microgel must be separated from the aqueous dispersion, purified, and dispersed again in an organic solvent. There was a limit to use as a material for application. Yamazaki et al. Have attempted to synthesize a reactive microgel in one step by emulsion-copolymerizing a polyfunctional monomer having a hydroxyl group, an epoxy group, and a polymerizable double bond group (Yamazaki,
Hattori, surface 1987, 25, 86). However, the functional groups that can be introduced by this method are extremely limited, and particularly, functional groups having polymerizable double bonds are attacked by radicals during emulsion polymerization and react. Synthesis of water-soluble microgels was difficult.

[0003]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies to overcome the drawbacks that the process for producing a reactive microgel is complicated and that the number of functional groups that can be introduced on the surface is large. By discovering the addition reactions that occur and using them, it is possible to quantitatively determine other functional groups other than epoxy groups, such as polymerizable double bonds and hydroxyl groups, without isolating the microgel from the aqueous dispersion. A production method that can be applied to a product has been found.

[0004]

That is, the present invention relates to a microgel fine particle (A) synthesized by emulsion polymerization of a monomer having a polymerizable double bond using a carboxyl group-containing compound as an emulsifier, and an epoxy group in one molecule. And a method for producing a reactive microgel, which comprises reacting the compound (B) with at least one other functional group. Monofunctional monomers having a polymerizable double bond include (a) (meth) acrylates:
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, ( C1 of (meth) acrylic acid such as lauryl (meth) acrylate
-C18 alkyl ester: glycidyl (meth) acrylate: C2-C20 alkenyl ester of (meth) acrylic acid such as allyl (meth) acrylate: hydroxylethyl (meth) acrylate, hydroxylethyl (meth) acrylate, hydroxypropyl (meth) acrylate C2 -C20 hydroxylalkyl esters of (meth) acrylic acid such as hydroxypropyl (meth) acrylate: C3 -C19 alkenyloxylalkyl esters of (meth) acrylic acid such as allyloxylethyl (meth) acrylate: (meth) acrylic acid (B)
Vinyl aromatic compounds: for example, styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, etc.
(C) Others: acrylonitrile, methacrylonitrile, methyl isopropenyl ketone: vinyl acetate, vinyl propionate and the like.

Next, polyfunctional monomers having two or more functional groups for three-dimensionally cross-linking the inside of microgel particles include (a) (meth) acrylates: trimethylolpropane tri (meth) acrylate (B) polyolefin compounds, such as di (meth) acrylates of glycols, di (meth) acrylates of polyols, di (meth) acrylates of polyurethanes, and di (meth) acrylates of polyesters : Butadiene, isoprene, chloroprene, divinylbenzene and the like. These monomers are appropriately selected depending on the desired physical properties, and may be used alone or in combination of two or more. However, when using a monofunctional monomer,
Since three-dimensional crosslinking is not performed by itself, it is necessary to use a polyfunctional reactive polymer emulsifier in combination with a polyfunctional monomer or as an emulsifier described later.

As the carboxyl group-containing compound, one having an effect as an emulsifier, usually a carboxyl group obtained by neutralizing the carboxyl group in the carboxyl group-containing compound with an alkali metal or ammonium or the like is used. Examples of such emulsifiers include low molecular weight emulsifiers such as caprylic acid, lauric acid, and stearic acid, or reactive monomers such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, and alkali metals and ammonium. And reactants. Further, as the polymer emulsifier, a homopolymer of a reaction product of a reactive monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, itaconic acid and an alkali metal or ammonium, or the above reactive monomer and an alkali Reaction products with metals or ammonium and other reactive monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate C1-C18 alkyl esters of (meth) acrylic acid such as: glycidyl (meth) acrylate: C2-C8 alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate:
C2 -C8 hydroxyalkyl esters of (meth) acrylic acid such as hydroxyethyl (meth) acrylate: vinyl monomers 1 selected from C3 -C19 alkenyloxyl alkyl esters of (meth) acrylic acid such as allyloxylethyl acrylate Those obtained by copolymerizing at least one species can be selected. When a polymer emulsifier, the reaction between a reactive monomer having a carboxyl group and an alkali metal or ammonia may be performed before homopolymerization or copolymerization with another vinyl monomer, as described above, The polymerization may be performed after homopolymerization or copolymerization with another vinyl monomer. These polymer emulsifiers can be used as such or as a reactive emulsifier into which a polymerizable double bond is introduced by reacting an epoxy group such as glycidyl (meth) acrylate with a part of a carboxyl group.

The above-mentioned polymer emulsifier can control the degree of water solubility, and is therefore a preferred emulsifier in applications requiring water resistance. Further, for the purpose of assisting emulsification, an anionic or nonionic low molecular surfactant may be used in combination with the above-mentioned polymer emulsifier as long as physical properties such as water resistance are not impaired.
These emulsifiers are used in an amount of 0.1 to 80% by weight, preferably 3 to 50% by weight, based on the compound having a polymerizable double bond, and the temperature of the emulsion polymerization is 50 to 95 ° C, preferably 65 to 95 ° C.
８０80 ° C. The solid content of the compound having a polymerizable double bond and the emulsifier during the emulsion polymerization is 10 to 50% by weight.
Desirably, it is 10 to 35% by weight. In the present invention,
The particle size of the microgel formed by emulsion polymerization is usually 10 to 200 μm as measured by a light scattering method.

The microgel particles (A) thus produced have carboxyl groups on the surface,
In the present invention, the carboxyl group is reacted with a compound (B) having an epoxy group which reacts with the carboxyl group and at least one other functional group in one molecule. Examples of the compound (B) include epoxy compounds having a polymerizable double bond such as glycidyl (meth) acrylate, N-glycidyl acrylamide, glycidyl allyl ether, 1,2-epoxy-5-hexene, and a hydroxyl group such as glycidol. Epoxy compounds and the like can be mentioned. These compounds (B) are appropriately selected according to the desired physical properties, may be used alone, or may be used in combination of two or more kinds thereof. The reaction can be performed at a free ratio up to 100 mol%. This reaction is carried out by mixing the epoxy compound with the aqueous microgel dispersion,
The stirring is completed only by stirring for 2 hours or more at a temperature of 60 ° C, preferably 60 to 80 ° C. Thus, in the present invention, there is an advantage that the reaction can be performed even in an aqueous dispersion.

The reactive microgel of the present invention is provided as an aqueous dispersion or as an organic solvent dispersion in which some or all of water is removed by azeotropic distillation with benzenes, alcohols, ketones and the like. When it is desired to use it in a dry state, it can be obtained by a usual method, preferably a method of coagulating an aqueous dispersion and then washing and drying the coagulated material to obtain fine powder, or a spray drying method. Monomers, oligomers, and high molecular compounds having a polymerizable double bond in the reactive microgel obtained in the present invention, or polymers having no polymerizable double bond for the purpose of satisfying the required characteristics of various uses Compounds and the like may be added and used as long as the intended purpose is not impaired.

[0010]

[Example 1]

(A) Synthesis of polymer emulsifier 90 parts of acrylic acid (neutralized with 70 mol% with sodium hydroxide), 10 parts of butyl acrylate, and 400 parts of deionized water were stirred in a 1-liter reaction vessel in a nitrogen atmosphere for 80 parts.
Warmed to ° C. Add 16 parts of 5% azobisamidinopropane dihydrochloride (hereinafter referred to as AAPD) aqueous solution and hold for 2 hours, then add 4 parts of 5% AAPD aqueous solution, and after completion of addition, keep the reaction mixture at 80 ° C. for 4 hours The polymerization was completed to obtain a polymer emulsifier. (B) Synthesis of reactive microgel 95 parts of styrene, 5 parts of divinylbenzene, 250 parts of polymer emulsifier prepared in (a) (solid content was adjusted to 20%),
While stirring 250 parts of deionized water in a 1 liter reaction vessel,
Heated to 80 ° C. in a nitrogen atmosphere. Add 16 parts of 5% AAPD aqueous solution and hold for 2 hours, then add 4 parts of 5% AAPD aqueous solution, and after completion of addition, keep the reaction mixture at 80 ° C. for 4 hours to complete polymerization, complete non-reactive microgel An aqueous dispersion was obtained. The measurement result of the microgel particle diameter in this dispersion by a light scattering method was about 100 nm. After leaving the obtained non-reactive microgel aqueous dispersion overnight, 17.8 parts of glycidyl methacrylate was added, the mixture was heated to 80 ° C. in an air atmosphere, and stirred for 4 hours to obtain a surface of the microgel. A reactive microgel aqueous dispersion having a polymerizable double bond was obtained.

Example 2 (c) Synthesis of reactive microgel 100 parts of R-45ACR-LC (dimethacrylate modified polybutadiene manufactured by Idemitsu Petrochemical Co., Ltd.), Emulgen 810
10 parts of nonionic surfactant (manufactured by Kao Corporation), 100 parts of the polymer emulsifier synthesized in Example 1- (a) (the solid content was adjusted to 20%), and 290 parts of deionized water in a 1 liter reaction vessel. The mixture was heated to 80 ° C. in a nitrogen atmosphere under stirring.
Add 16 parts of 5% AAPD aqueous solution and hold for 2 hours, then add 4 parts of 5% AAPD aqueous solution, and after completion of addition, keep the reaction mixture at 80 ° C. for 4 hours to complete polymerization, complete non-reactive microgel An aqueous dispersion was obtained. The measurement result of the microgel particle diameter in this dispersion by the light scattering method was about 200 nm.
Met. After leaving the obtained non-reactive microgel aqueous dispersion overnight, 7.1 parts of glycidyl methacrylate was added, the mixture was heated to 80 ° C. in an air atmosphere, and stirred for 4 hours to obtain a surface of the microgel. A reactive microgel aqueous dispersion having a polymerizable double bond was obtained.

Comparative Example 1 A non-reactive microgel aqueous dispersion in Example 1 to which glycidyl methacrylate was not added is referred to as Comparative Example 1. Comparative Example 2 The non-reactive microgel aqueous dispersion in Example 2 to which glycidyl methacrylate was not added is referred to as Comparative Example 2.

[Evaluation of Physical Properties] Reactive microgels as means for improving the physical properties of acrylic resins were evaluated. That is, the characteristics of the reactive microgel as a photosensitive resin were evaluated as follows. The aqueous reactive microgel dispersions and non-reactive microgel aqueous dispersions of Examples 1 and 2 and Comparative Examples 1 and 2 were 50% (solid content ratio) to the aqueous solution of the photosensitive acrylic resin and the aqueous solution of the non-photosensitive acrylic resin. And Darocur 2959 as a photoinitiator was added at 5% based on the total solid content. Example 1 was used as a non-photosensitive acrylic resin.
The polymer emulsifier synthesized in (a) was used. Further, as the photosensitive acrylic resin, a resin obtained by modifying 10% of the carboxyl groups of the polymer emulsifier with glycidyl methacrylate was used. Using this mixed solution, a film having a thickness of about 200 μm was prepared by a casting method,
It was cured by irradiating it with UV light of J. The film after ultraviolet irradiation was cut into strips having a width of 10 mm, and the tensile strength of the film was measured using a tensile tester at a pulling speed of 30 mm.
/ Min. Table 1 shows the results of measuring the tensile strength of a film obtained by adding a reactive microgel and a non-reactive microgel to a photosensitive acrylic resin and a non-photosensitive acrylic resin after irradiation with ultraviolet light.

[0014]

[Table 1]

Example 3 In Example 1, glycidol was used instead of 17.8 parts of glycidyl methacrylate.
A reactive microgel having a hydroxyl group on the surface was prepared in exactly the same manner as in Example 1 except that 3 parts were used.

[0015]

The reactive microgel of the present invention can be added to various polymer materials depending on the surface functional group,
It contributes to improvements in photosensitivity, strength, etc. In particular, reactive microgels having polymerizable double bonds on the surface are used for paints, inks,
It can be widely used for photosensitive materials such as photocurable adhesives, printed boards, and printing plates.

Claims (2)

(57) [Claims] 1. A microgel fine particle (A) synthesized by emulsion polymerization of a monomer having a polymerizable double bond using a carboxyl group-containing compound as an emulsifier, and an epoxy group and at least one other functional group in one molecule. A method for producing a reactive microgel, which comprises reacting a reactive microgel with a compound (B). 2. The method for producing a reactive microgel according to claim 1, wherein in the compound (B), at least one other functional group is a polymerizable double bond. [0001]