JP2019077795A - Method for producing coated material - Google Patents

Abstract

To provide a method for producing a coated material in which a specific low molecular compound is uniformly coated on a vinyl alcohol-based polymer and fusion is reduced.SOLUTION: There is provided a method for producing a coated material obtained by coating a compound (B) on a vinyl alcohol-based polymer (A), which comprises: a liquid preparation step of preparing a coating liquid (D) by dissolving a compound (B) having a molecular weight of 70 or more and 300 or less and having at least one functional group selected from the group consisting of a carboxyl group, an ether group, an epoxy group and an amide group in a solvent (C) which contains methyl acetate and methanol and has a mass ratio of methyl acetate to methanol of 20/80 to 100/0; a mixing step of adding the vinyl alcohol-based polymer (A) to the coating liquid (D) to obtain a mixture; and a drying step of removing the solvent (C) from the mixture.SELECTED DRAWING: None

Description

  The present invention comprises the steps of mixing a vinyl alcohol polymer with a coating solution containing a specific low molecular compound and a solvent, and drying and removing the solvent, wherein the low molecular compound is coated on the vinyl alcohol polymer The present invention relates to a method of producing a coated article.

  A vinyl alcohol polymer (hereinafter sometimes abbreviated as "PVA") is conventionally an adhesive, a paper coating agent, a polarizing film, a water-soluble film, a composition for pharmaceutical or cosmetic use, a vinyl compound (for example, It is used as a dispersion stabilizer for suspension polymerization of vinyl chloride).

  In order to further improve the performance in various applications, it is practiced to introduce a specific functional group in PVA by post-modification, and one of the raw materials of the post-modification is a low molecular weight having a specific functional group Coatings in which the compound is coated on PVA are used. In post-modification, for example, in Patent Document 1, a coated material in which an unsaturated carboxylic acid compound is coated on PVA is used as a raw material when the reaction of the unsaturated carboxylic acid compound and PVA is performed. The coating is obtained by dissolving the unsaturated carboxylic acid compound with methanol, soaking the PVA, and removing the methanol by drying.

  However, in the method described in Patent Document 1, there are problems such as fusion occurring in the coating, long time and energy required for drying, and poor productivity, probably because the coating is not uniform.

International Publication 2007/119735

  An object of the present invention is to provide a production method in which a coating having a reduced adhesion, in which a vinyl alcohol polymer is uniformly coated with a specific compound, and which has reduced fusion, can be easily obtained with good productivity.

  As a result of intensive studies to solve the above problems, the inventor of the present invention is a method for producing a coated product obtained by coating a vinyl alcohol polymer (A) with a specific compound (B), which is a compound ( The vinyl alcohol polymer (A) is mixed with the coating solution (D) containing B) and a specific solvent (C), and then dried and the solvent (C) is removed by the method for producing a coated film. It has been found that the problems can be solved, and the present invention has been completed after intensive studies.

  That is, the above-mentioned subject is a manufacturing method of a covering thing which coats a vinyl alcohol polymer (A) with a compound (B), and molecular weight is 70 or more and 300 or less, and a carboxy group, an ether group, an epoxy group And a compound (B) having at least one functional group selected from the group consisting of and an amide group, containing methyl acetate and methanol, and the mass ratio thereof is methyl acetate / methanol = 20/80 to 100/0 Preparation of a coating solution (D) by dissolving in C), adding a vinyl alcohol polymer (A) to the coating solution (D) to obtain a mixture, and mixing the solvent (C) from the above mixture The problem is solved by providing a process for the production of a coating having a drying step which is removed.

  At this time, it is preferable that the compounding quantity of the coating liquid (D) in a mixing process is 50 mass parts or more and 300 mass parts or less with respect to 100 mass parts of vinyl alcohol polymer (A). Moreover, it is also preferable that the compounding quantity of the compound (B) in a mixing process at this time is 0.1 mass part or more and 50 mass parts or less with respect to 100 mass parts of vinyl alcohol polymer (A).

  Furthermore, it is also preferable that the degree of saponification of the vinyl alcohol polymer (A) is 68 mol% or more and 99.9 mol% or less.

  According to the production method of the present invention, it is possible to easily obtain a coating in which a vinyl alcohol polymer is uniformly coated with a specific low molecular weight compound. Furthermore, the resulting coatings have reduced adhesion.

  The present invention relates to a method for producing a coated product obtained by coating a compound (B) on a vinyl alcohol polymer (A) (hereinafter sometimes abbreviated as "PVA (A)"), which has a molecular weight of 70 The compound (B) having at least one functional group selected from the group consisting of a carboxy group, an ether group, an epoxy group and an amido group which contains at least 300 and no more than 300 contains methyl acetate and methanol, and its mass ratio is methyl acetate Preparation of a coating solution (D) by dissolving in a solvent (C) of 20/80 to 100/0 / methanol, adding a vinyl alcohol polymer (A) to the coating solution (D) and mixing the mixture And a drying step of removing the solvent (C) from the above mixture. In addition, although the coating material in this invention means the thing by which the compound (B) was coated on the surface of PVA (A), a part of compound (B) permeates the inside of PVA (A). It does not matter.

  Hereinafter, the method for producing the coated article of the present invention will be described in detail. The present invention is not limited to the embodiments described below. Further, in the present specification, the upper limit value and the lower limit value of the numerical range (the content of each component, the value calculated from each component, each physical property, and the like) can be combined as appropriate.

[Mixing process]
In the liquid preparation step, the compound (B) having a molecular weight of 70 to 300 and having at least one functional group selected from the group consisting of a carboxy group, an ether group, an epoxy group and an amide group contains methyl acetate and methanol. The coating solution (D) is obtained by dissolving in a solvent (C) having a mass ratio of methyl acetate / methanol = 20/80 to 100/0.

(Compound (B))
It is important that the compound (B) has a molecular weight of 70 or more and 300 or less. When the molecular weight is less than 70, the handleability is insufficient because the boiling point is low. On the other hand, when the molecular weight exceeds 300, the solubility in the solvent (C) and the affinity for the PVA (A) become insufficient.

  Furthermore, it is important that the compound (B) has at least one functional group selected from the group consisting of a carboxy group, an ether group, an epoxy group and an amide group. Among them, when the resulting coated product is used for post-modification applications, a carboxy group or an epoxy group is preferable from the viewpoint of reactivity.

  Among the compounds (B), as a compound having a carboxy group, for example, lactic acid; gallic acid; ibuprofen; saturated monocarboxylic acids such as butanoic acid, pentanoic acid, hexanoic acid, capric acid or derivatives thereof; succinic acid, malonic acid, Saturated dicarboxylic acids such as malic acid or derivatives thereof; acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, propynoic acid, 2-pentenoic acid, 4-pentenoic acid, 2-heptenoic acid, 2-octenoic acid, cinnamic acid, Unsaturated monocarboxylic acids such as sorbic acid or derivatives thereof; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid or derivatives thereof, and the like. Examples of derivatives of carboxylic acid include metal salts of carboxylic acids, carboxylic acid anhydrides, carboxylic acid alkyl esters and the like. Among the compounds (B), examples of compounds having an ether group include dipropyl ether, dibutyl ether, cyclopentyl methyl ether and the like, and compounds having an epoxy group include allyl glycidyl ether, styrene oxide, butylene oxide, hexane oxide and the like Examples of the compound having an amido group include N, N-diethyl-3-methylbenzamide, acetaminophen, crotamiton, monofluoroacetic acid amide and the like. Among them, unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, unsaturated dicarboxylic acid monoalkyl esters or unsaturated dicarboxylic acid anhydrides are preferable from the viewpoint of affinity with PVA (A), for example, acrylic acid, methacrylic acid, Preferred are itaconic acid, fumaric acid, citraconic acid, monomethyl maleate, monomethyl itaconate, maleic anhydride, itaconic anhydride, acrylic anhydride and methacrylic anhydride.

(Solvent (C))
It is important that the solvent (C) contains methyl acetate and methanol, and the mass ratio thereof is methyl acetate / methanol = 20/80 to 100/0. When the mass ratio of methyl acetate is less than 20, in the drying step of removing the solvent (C), it takes a long time to dry and the productivity is lowered, a part of the PVA is dissolved and the PVAs are fused to each other. There are problems such as non-uniform progress and generation of water insoluble matter in the dried coating. The mass ratio of methyl acetate / methanol is preferably 25/75 to 95/5, and more preferably 30/70 to 90/10, from the viewpoint of the solubility of the compound (B) and the affinity to PVA (A).

  The solvent (C) may contain methyl acetate and methanol in the above mass ratio, and in addition to methyl acetate and methanol, may contain other solvents such as ethanol, isopropanol, dimethyl sulfoxide, diethyl sulfoxide, dimethylformamide and the like It is also good. Although there is no restriction | limiting in particular in content of another solvent, 10 mass% or less is preferable with respect to whole quantity of a solvent (C), and 5 mass% or less is more preferable.

[Mixing process]
In the mixing step, PVA (A) is added to the coating solution (D) to obtain a mixture.

(PVA (A))
The viscosity average polymerization degree of PVA (A) is not particularly limited, but is preferably 200 or more and 3,500 or less from the viewpoint of productivity. The viscosity average degree of polymerization is a value obtained by measurement according to JIS-K6726 (1994). Specifically, when the degree of saponification is less than 99.5 mol%, the limiting viscosity [.eta.] (L / L) measured at 30.degree. C. in water for PVA saponified to a degree of saponification of 99.5 mol% or more Viscosity average polymerization degree (P) was calculated | required by the following formula using g).

P = ([η] × 10 ⁴ /8.29) ^{(1 / 0.62)}
Although there is no restriction | limiting in particular in the saponification degree of PVA (A), More than 68 mol% and 99.9 mol% or less are preferable. The degree of saponification is a value obtained by measurement according to JIS-K6726 (1994). When the degree of saponification of PVA (A) is less than 68 mol%, the water solubility of PVA (A) obtained tends to decrease, and the handling property when applied to various applications tends to decrease. On the other hand, PVA having a degree of saponification of more than 99.9 mol% tends to be difficult to produce.

  Although there is no restriction | limiting in particular in the manufacturing method of PVA (A), Usually, it is obtained by saponifying this vinyl-ester type polymer, after polymerizing a vinyl-ester type monomer and obtaining a vinyl-ester type polymer. As a polymerization method, conventionally known methods such as bulk polymerization method, solution polymerization method, suspension polymerization method, emulsion polymerization method and dispersion polymerization method can be adopted. From the industrial viewpoint, solution polymerization, emulsion polymerization or dispersion polymerization is preferred. In the polymerization operation, any polymerization method of batch method, semi-batch method and continuous method can be adopted.

  Examples of the vinyl ester-based monomer include vinyl acetate, vinyl formate, vinyl propionate, vinyl caprylate, vinyl versatate and the like, among which vinyl acetate is preferable from the industrial viewpoint.

  In the polymerization of the vinyl ester monomer, another monomer may be copolymerized as long as the purpose of the present invention is not impaired. Examples of such other monomers include α-olefins such as ethylene and propylene; (meth) acrylic acid and salts thereof; methyl (meth) acrylate, ethyl (meth) acrylate and n- (meth) acrylate Propyl, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) (Meth) acrylic esters such as dodecyl acrylate, octadecyl (meth) acrylate; (meth) acrylamides; N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide , Diacetone (meth) acrylamide, (meth) acrylamidopropane sulfonic acid and salts thereof, Acrylamidopropyldimethylamine and salts thereof or quaternary salts thereof, (meth) acrylamide derivatives such as N-methylol (meth) acrylamide and derivatives thereof; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl Vinyl ethers such as vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether; nitriles such as acrylonitrile and methacrylonitrile; halogenated vinyls such as vinyl chloride and vinyl fluoride; vinylidene chloride, fluoride Vinylidene halides such as vinylidene; allyl compounds such as allyl acetate and allyl chloride; unsaturated dicarboxylic acids such as maleic acid, itaconic acid and fumaric acid; The salts thereof or esters thereof; vinylsilyl compounds such as vinyltrimethoxysilane; and isopropenyl acetate. When such other monomers are copolymerized, the amount of copolymerization is usually 5 mol% or less.

  In addition, in the polymerization of the vinyl ester monomer, a chain transfer agent may be coexistent for the purpose of adjusting the viscosity average polymerization degree of the resulting vinyl ester polymer. As a chain transfer agent, aldehydes such as acetaldehyde, propionaldehyde, butyraldehyde and benzaldehyde; ketones such as acetone, methyl ethyl ketone, hexanone and cyclohexanone; mercaptans such as 2-hydroxyethanethiol and dodecyl mercaptan; trichloroethylene and perchloroethylene And halogenated hydrocarbons, and among them, aldehydes and ketones are preferably used. The amount of chain transfer agent added is determined according to the chain transfer constant of the chain transfer agent to be added and the viscosity average degree of polymerization of the target vinyl ester polymer, but in general, the amount relative to the vinyl ester monomer is It is 0.1-10 mass%.

  In the saponification reaction of a vinyl ester polymer, alcoholysis or hydrolysis is carried out using a conventionally known basic catalyst such as sodium hydroxide, potassium hydroxide, sodium methoxide or an acidic catalyst such as p-toluenesulfonic acid. The decomposition reaction can be applied. Examples of the solvent used for the saponification reaction include alcohols such as methanol and ethanol; esters such as methyl acetate and ethyl acetate; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as benzene and toluene; These can be used alone or in combination of two or more. Among them, it is convenient and preferable to carry out the saponification reaction in the presence of sodium hydroxide which is a basic catalyst, using methanol or a mixed solution of methanol and methyl acetate as a solvent.

  The form of PVA (A) is not particularly limited, but is preferably particles from the viewpoint of more uniformly coating the compound (B). The particle diameter of the particles comprising PVA (A) is usually 50 to 2000 μm. The particle size of the powder is an average particle size obtained by the method of JIS-K6726 (1994).

  50 mass parts or more and 300 mass parts or less are preferable with respect to 100 mass parts of PVA (A), and, as for the compounding quantity of the coating liquid (D) in a mixing process, 60 mass parts or more and 250 mass parts or less are more preferable. When the blending amount of the coating liquid (D) is less than 50 parts by mass, unevenness of the coating tends to occur. On the other hand, when the compounding amount exceeds 300 parts by mass, the drying step of removing the solvent (C) takes a lot of energy and time, so the productivity tends to be lowered.

  Moreover, 0.1 mass part or more and 50 mass parts or less are preferable with respect to 100 mass parts of PVA (A), and, as for the compounding quantity of a compound (B) in a mixing process, 1 mass part or more and 40 mass parts or less are more preferable. If the compounding amount of the compound (B) is less than 0.1 parts by mass, the coated compound (B) tends to be difficult to improve the performance in various uses as a coated material. On the other hand, when the compounding amount exceeds 50 parts by mass, the coated compound (B) tends to be easily peeled off.

[Drying process]
In the drying step, the solvent (C) is removed from the above mixture obtained in the mixing step. There is no restriction | limiting in particular in the drying temperature of the said mixture, It can set arbitrarily from lyophilization | freeze-drying under a freezing point to about 230 degreeC which is a decomposition temperature of PVA (A). From the viewpoint of productivity and economy, 20 ° C. or more and 180 ° C. or less are preferable, and 20 ° C. or more and 150 ° C. or less are more preferable.

[Application of Coating]
The coatings obtained by the process of the invention can be used in various applications. Although the example is given to the following, it is not limited to this.
(1) Dispersants Applications: Dispersion stabilizers for organic and inorganic pigments such as paints and adhesives, Dispersion stabilizers for suspension polymerization of various vinyl compounds such as vinyl chloride, vinylidene chloride, styrene, (meth) acrylate and vinyl acetate And dispersion aids (2) adhesives Applications: adhesives, adhesives, remoistening adhesives, various binders, additives for cement and mortar (3) coatings Applications: paper coatings, sizing agents, fiber processing agents, Leather finish, paint, anti-fogging agent, metal corrosion inhibitor, brightener for galvanizing, antistatic agent, pharmaceutical coating agent (4) Emulsifier application: Emulsifier for emulsion polymerization, post-emulsifier such as bitumen (5) Flocculant application : Coagulants for suspended and dissolved in water, metal flocculants (6) molding applications: fibers, sheets, pipes, tubes, leakproof film, water soluble fibers for chemical races, sponges (7) film applications: water soluble film ,side Film, barrier film (8) drug controlled release application: coating for medicine, soil modifier, pesticide additive, medicine additive (9) post modification Use: after low molecular weight organic compound, high molecular weight organic compound, inorganic compound Modification use

 Among them, preferred applications of the coating obtained by the production method of the present invention are the above (8) drug sustained release application and (9) post-denaturing application.

  When the coating is used as a post-modification application, it is possible to utilize PVA (A) as a reaction site to react another compound capable of reacting with the coated compound (B). Moreover, it is also possible to make PVA (A) and the coated compound (B) react. These post-denaturing can be performed under any reaction conditions.

  Hereinafter, the present invention will be described in more detail by way of examples. In the following Examples and Comparative Examples, "parts" and "%" indicate parts by mass and% by mass, respectively, unless otherwise noted.

[Viscosity average degree of polymerization of PVA (A)]
The viscosity average polymerization degree of PVA (A) was measured according to JIS-K6726 (1994). Specifically, when the degree of saponification is less than 99.5 mol%, the limiting viscosity [.eta.] (L / L) measured at 30.degree. C. in water for PVA saponified to a degree of saponification of 99.5 mol% or more Viscosity average polymerization degree (P) was calculated | required by the following formula using g).
P = ([η] × 10 ⁴ /8.29) ^{(1 / 0.62)}

[Saponification degree of PVA (A)]
The degree of saponification of PVA (A) was determined by the method described in JIS-K6726 (1994).

[Shape of PVA (A)]
The shape of PVA (A) used by the manufacturing method mentioned later was particle | grains, and the average particle diameter calculated | required by the method of JIS-K6726 (1994) was 500-600 micrometers.

[Fusion of coating]
The coated material obtained by the manufacturing method described later was placed in a polyethylene bag, lightly shaken by hand, and then taken out. The degree of fusion between the particles of the coating was evaluated by visual inspection and mass measurement of the fused mass according to the following criteria. In the case where the particles of the coating are fused to a large extent, the sustained release tends to deteriorate when it is used for the subsequent use, for example, drug sustained release application, or uneven reaction occurs when it is used for post-modification.
A: Almost no fusion of the particles of the coating was observed.
B: Some fusion of particles of the coating was observed.
C: Many fusion of particles of the coating was observed.

Example 1
A compound (B) was dissolved in 3 parts of allyl glycidyl ether having a molecular weight of 114, and a solvent (C) was dissolved in 100 parts of methyl acetate to prepare 103 parts of a coating liquid (D). Subsequently, 50 parts of PVA having a viscosity average polymerization degree of 500 and a saponification degree of 80 mol% as PVA (A) was added to the above coating liquid (D), and the mixture was further immersed for 10 minutes to obtain a mixture. At this time, the compounding amount of the compound (B) was 6 parts and the compounding amount of the coating liquid (D) was 206 parts with respect to 100 parts of PVA (A). Thereafter, the solvent (C) was removed from the above mixture using a vacuum drier at room temperature (20 ° C.) to obtain a coated product. When the degree of fusion was evaluated for the obtained coating by the above-mentioned method, almost no fusion was observed.

(Examples 2 to 10, Comparative Example 1 and Comparative Example 2)
The coated product in the same manner as in Example 1 except that the type and compounding amount of compound (B), the composition ratio and compounding amount of solvent (C), and the type and compounding amount of PVA (A) are changed as shown in Table 1. Production of The results are shown in Table 1.

As shown in the examples, according to the manufacturing method of the present invention, a coating with less fusion is obtained. Since the adhesion of the coating is low, it can be expected to reduce reaction unevenness in subsequent use, for example, post-modification applications, and the industrial usefulness of the present invention is extremely high.

Claims (4)

A method for producing a coated product obtained by coating a vinyl alcohol polymer (A) with a compound (B),
A compound (B) having a molecular weight of 70 or more and 300 or less and having at least one functional group selected from the group consisting of a carboxy group, an ether group, an epoxy group and an amide group contains methyl acetate and methanol, and its mass ratio Preparation step in which a coating solution (D) is obtained by dissolving in a solvent (C) in which methyl acetate / methanol = 20/80 to 100/0,
A mixing step of adding the vinyl alcohol polymer (A) to the coating liquid (D) to obtain a mixture, and a drying step of removing the solvent (C) from the above mixture,
A method of producing a coating having:   The manufacturing method of the coating material of Claim 1 whose compounding quantity of the coating liquid (D) in a mixing process is 50 mass parts or more and 300 mass parts or less with respect to 100 mass parts of vinyl alcohol polymer (A).   The coating material according to claim 1 or 2, wherein the compounding amount of the compound (B) in the mixing step is 0.1 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the vinyl alcohol polymer (A). Production method.   The manufacturing method of the coating material in any one of Claims 1-3 whose saponification degree of a vinyl alcohol polymer (A) is 68 to 99.9 mol%.