JP2022167850A - Resin composition for emulsion, and coating agent - Google Patents

Abstract

To provide a resin composition for an emulsion which facilitates production of an emulsion composition even while containing an aliphatic polyester-based resin, and enables production of an emulsion composition excellent in safety.SOLUTION: A resin composition for an emulsion contains (A) an aliphatic polyester-based resin, and (B) a cellulose acetate-based resin.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a resin composition for emulsion containing a biodegradable resin. More particularly, it relates to emulsion resin compositions and coating agents containing aliphatic polyester resins.

In recent years, against the background of the demand for reducing the burden on the environment, research and development on various biodegradable resins are progressing. Among them, from the viewpoint of promoting the elimination of organic solvents, a resin composition for emulsion containing a biodegradable resin has attracted attention.

For example, as an emulsion resin composition having excellent biodegradability, an emulsion composition obtained by emulsifying an aliphatic polyester resin such as polylactic acid or polybutylene succinate using a dispersant such as polyvinyl alcohol has been proposed. Development of various applications such as adhesives, paints, and coating agents is expected (Patent Document 1).

Japanese Unexamined Patent Application Publication No. 2004-204038

However, it is sometimes difficult to produce an emulsion resin composition containing an aliphatic polyester resin using an extruder or the like, and the stability of the obtained emulsion composition may be insufficient. , there is still room for improvement.

Moreover, even if it is possible to produce an emulsion composition with a certain level of stability, there are cases where the properties required of the coating agent, such as film-forming properties and heat-sealing properties, are insufficient. Further improvement is required from

The present invention has been made in view of the above-mentioned problems, and is an emulsion resin that facilitates the production of an emulsion composition while containing an aliphatic polyester resin and provides an emulsion composition that is excellent in stability. The object is to provide a composition and the like.

Another object of the present invention is to provide a resin composition for emulsion, etc., from which an emulsion composition having excellent film-forming properties and heat-sealing properties can be obtained.

As a result of intensive research in view of such circumstances, the inventors of the present invention unexpectedly found that the production of an emulsion composition became easier by blending a specific resin together with an aliphatic polyester-based resin. The present invention was completed by discovering that the stability of

In addition, as a result of extensive research in view of such circumstances, the present inventors unexpectedly found an emulsion composition excellent in film-forming properties and heat-sealing properties by blending a specific resin together with an aliphatic polyester resin. The present invention was completed by discovering that a product can be obtained.

The present invention provides the following [1] to [19].
[1] A resin composition for emulsion containing (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin.
[2] According to [1], the mass ratio [(B)/(A)] of the (B) cellulose acetate-based resin to the (A) aliphatic polyester-based resin is 0.05 to 0.5. Resin composition for emulsion.
[3] The resin composition for emulsion according to [1] or [2], wherein the resin composition for emulsion has a melt flow rate of 8 g/10 minutes or more at 190° C. and 2.16 kg.
[4] The resin composition for emulsion according to any one of [1] to [3], which contains cellulose acetate butyrate as the cellulose acetate resin (B).
[5] The emulsion resin composition according to any one of [1] to [4], further comprising (C) a dispersant.
[6] The emulsion resin composition according to any one of [1] to [5], which is a water-based emulsion resin composition further containing water.
[7] An emulsion composition containing the emulsion resin composition according to any one of [1] to [4].
[8] An emulsion composition containing the resin composition for emulsion according to [5].
[9] An emulsion composition containing the resin composition for emulsion according to [6].
[10] A coating agent containing the emulsion resin composition according to any one of [1] to [6].
[11] The coating agent according to [10], wherein the object to be coated is a paper substrate.
[12] The coating agent of [10], wherein the object to be coated is a plastic substrate.
[13] A molded article using the emulsion resin composition according to any one of [1] to [6].
[14] A film using the resin composition for emulsion according to any one of [1] to [6].
[15] A cosmetic containing the emulsion resin composition according to any one of [1] to [6].
[16] An agricultural composition containing the emulsion resin composition according to any one of [1] to [6].
[17] A paint containing the emulsion resin composition according to any one of [1] to [6].
[18] An ink containing the emulsion resin composition according to any one of [1] to [6].
[19] A pressure-sensitive adhesive containing the emulsion resin composition according to any one of [1] to [6].

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a resin composition for emulsion, etc., which facilitates the production of an emulsion composition while containing an aliphatic polyester-based resin, and which is capable of obtaining an emulsion composition having excellent stability. be able to.

Further, according to the present invention, it is possible to provide a resin composition for emulsion, etc., which can obtain an emulsion composition excellent in film-forming properties and heat-sealing properties.

Hereinafter, the present invention will be described in more detail based on embodiments of the present invention, but the present invention is not limited to these embodiments.

In this specification, when expressing "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or " It also includes the meaning of "preferably smaller than Y".
In addition, when expressing "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), the statement "preferably larger than X" or "preferably less than Y" It also includes intent.
Furthermore, "X and/or Y (where X and Y are arbitrary configurations)" means at least one of X and Y, and means X only, Y only, and X and Y.

An emulsion resin composition according to an example of the embodiment of the present invention is an emulsion resin composition containing (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin. The resin composition for emulsion according to an example of the embodiment of the present invention contains (A) an aliphatic polyester resin and (B) a cellulose acetate resin as dispersoids, further (C) a dispersant, and ( D) A water-based emulsion resin composition containing a dispersion medium is suitable.
Moreover, an emulsion composition containing the emulsion resin composition according to one example of the embodiment of the present invention is suitable. Such an emulsion composition is obtained by a known production method such as a phase inversion emulsification method using the resin composition for emulsion according to one example of the embodiment of the present invention.

[(A) Aliphatic polyester resin]
Component (A) is not particularly limited as long as it is a polyester resin in which the molar ratio of the aliphatic structure (including the alicyclic structure) is the maximum ratio with respect to the overall structure. It may be an aliphatic-aromatic polyester-based resin having an aromatic structure in it. More specifically, for example, (A1) an aliphatic polyester resin having an aliphatic diol unit and an aliphatic dicarboxylic acid unit as main structural units; (A2) an aliphatic having an aliphatic oxycarboxylic acid unit as a main structural unit polyester-based resins; (A3) aliphatic-aromatic polyester-based resins having aliphatic diol units, aliphatic dicarboxylic acid units, and aromatic dicarboxylic acid units as main structural units; and mixtures thereof. Among these, (A1) an aliphatic polyester resin having an aliphatic diol unit and an aliphatic dicarboxylic acid unit as main structural units is preferable.

Here, the "unit" means a structural unit contained in the aliphatic polyester resin derived from the monomer component used in the production of the aliphatic polyester resin, and the "main structural unit" It means that 50 mol % or more of the total structural units of the aliphatic polyester-based resin are contained in the structural units derived from the target monomer component. The content of structural units derived from the target monomer is preferably 60 mol % or more, more preferably 70 mol % or more, and even more preferably 80 to 100 mol %. For example, the aliphatic diol and the aliphatic dicarboxylic acid component are 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more in the total monomer components used in the polymerization reaction of the aliphatic polyester resin. More preferably, it is produced by polymerizing a raw material containing 80 to 100 mol %.

[(A1) Aliphatic Polyester Resin Having Aliphatic Diol Units and Aliphatic Dicarboxylic Acid Units as Main Structural Units]
The component (A1) is, for example, an aliphatic polyester resin having, as main structural units, an aliphatic diol unit represented by the following formula (1) and an aliphatic dicarboxylic acid unit represented by the following formula (2).

-OR ₁₁ -O- (1)
[In formula (1), R ₁₁ represents a divalent chain aliphatic hydrocarbon group which may have an oxygen atom in the chain, and when copolymerized, it is not limited to one type. ]

-OC-R21-CO- ₍ 2)
[In formula (2), R ₂₁ represents a direct bond or represents a divalent chain aliphatic hydrocarbon group, and when it is copolymerized, it is not limited to one type. ]

The aliphatic diol that gives the diol unit of formula (1) is not particularly limited, but for example, an aliphatic diol having 2 to 10 carbon atoms is preferable, and an aliphatic diol having 4 to 6 carbon atoms is more preferable. Specifically, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptane diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and the like. Among them, 1,4-butanediol is preferred. The aliphatic diols may be used singly or in combination of two or more.

The aliphatic dicarboxylic acid component that gives the aliphatic dicarboxylic acid unit of formula (2) is an aliphatic dicarboxylic acid or an aliphatic dicarboxylic acid derivative such as an alkyl ester thereof, and the aliphatic dicarboxylic acid is not particularly limited, but For example, aliphatic dicarboxylic acids having 2 to 40 carbon atoms are preferred, and aliphatic dicarboxylic acids having 4 to 10 carbon atoms are more preferred. Specific examples include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid and the like. Among them, succinic acid, adipic acid and sebacic acid are preferred, succinic acid and adipic acid are more preferred, and succinic acid is particularly preferred. The aliphatic dicarboxylic acid components may be used alone or in combination of two or more.

Specific examples of the component (A1) include aliphatic polyester resins containing 1,4-butanediol and succinic acid, and aliphatic polyester resins containing 1,4-butanediol, adipic acid, and succinic acid. mentioned. More specific examples include polybutylene succinate, polybutylene succinate adipate, and the like. Among these, polybutylene succinate and polybutylene succinate adipate are preferred.

When the aliphatic dicarboxylic acid is succinic acid, the proportion of structural units derived from succinic acid in the total dicarboxylic acid units of the aliphatic polyester resin is usually 50 to 100 mol%, preferably 80 to 100 mol%, more preferably is 90 to 100 mol %.

Further, when the aliphatic dicarboxylic acid is succinic acid and adipic acid, the ratio of structural units derived from succinic acid in the total dicarboxylic acid units of the aliphatic polyester resin is usually 50 to 95 mol%, preferably 60 to 93. mol %, more preferably 70 to 90 mol %, and the proportion of structural units derived from adipic acid in all dicarboxylic acid units is usually 5 to 50 mol %, preferably 7 to 40 mol %, more preferably 10 to 30 mol %.

The (A1) component preferably has the following physical properties.

The weight average molecular weight (Mw) of component (A1) is preferably 10,000 or more, more preferably 20,000 or more, still more preferably 50,000 or more, and preferably 1,000,000 or less, and more preferably 1,000,000 or less. It is preferably 500,000 or less, more preferably 400,000 or less.
The weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The melt flow rate (MFR) of component (A1) is usually 0.1 g/10 minutes or more, preferably 0.5 g/10 minutes or more, more preferably 1 g/10 minutes, when measured at 190°C and 2.16 kg. It is 10 minutes or more, and is usually 1,000 g/10 minutes or less, preferably 500 g/10 minutes or less, more preferably 100 g/10 minutes or less, still more preferably 50 g/10 minutes or less.

The melting point of component (A1) is preferably 70° C. or higher, more preferably 75° C. or higher, and is preferably 250° C. or lower, more preferably 200° C. or lower, and particularly preferably 150° C. or lower. When there are multiple melting points, at least one melting point is preferably within the above range.

In addition, the physical properties of the (A) aliphatic polyester resin used in the present invention are, unless otherwise specified, [(A1) an aliphatic polyester resin having an aliphatic diol unit and an aliphatic dicarboxylic acid unit as main structural units ] are the same as the physical properties described in the section above.

[(A2) Aliphatic polyester resin having an aliphatic oxycarboxylic acid unit as a main structural unit]
Specific examples of the aliphatic oxycarboxylic acid component that provides the aliphatic oxycarboxylic acid unit of component (A2) include, for example, lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, 3-hydroxyvaleric acid, malic acid, citric acid etc., or lower alkyl esters or intramolecular esters thereof. Lactone compounds such as ε-caprolactone are also included in aliphatic oxycarboxylic acids in the present invention. When optical isomers are present in these compounds, they may be D-, L-, or racemic isomers, and may be solid, liquid, or aqueous solution. Among these, lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 6-hydroxycaproic acid, and 3-hydroxyvaleric acid are preferred. These aliphatic oxycarboxylic acids may be used alone or in combination of two or more.

Specific examples of component (A2) include polylactic acid, polyglycolic acid, poly-3-hydroxybutyrate, poly-4-hydroxybutyrate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polycaprolactone and the like.

As for the composition of lactic acid contained in polylactic acid, the molar ratio of D-lactic acid:L-lactic acid is preferably 100:0 to 85:15 or 0:100 to 15:85. It is also possible to blend other polylactic acids having different composition ratios of D-lactic acid and L-lactic acid. Polylactic acid having only D-lactic acid or only L-lactic acid as a structural unit tends to be a crystalline resin, has a high melting point, and tends to be excellent in heat resistance and mechanical properties.

Furthermore, the polylactic acid may be a copolymer of the aforementioned polylactic acid and other oxycarboxylic acid, and may contain a small amount of units derived from a chain extender. Other oxycarboxylic acids include optical isomers of lactic acid (D-lactic acid for L-lactic acid, L-lactic acid for D-lactic acid), glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, Bifunctional aliphatic oxycarboxylic acids such as 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, and caprolactone , butyrolactone, valerolactone, and other lactones. Units derived from such other oxycarboxylic acids are preferably used in an amount of less than 15 mol % of all structural units of polylactic acid.

The weight average molecular weight (Mw) of component (A2) is preferably 60,000 or more, more preferably 80,000 or more, particularly preferably 100,000 or more, and preferably 700,000 or less, more preferably 400,000 or less, particularly preferably 300,000 or less.
The weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[(A3) Aliphatic Aromatic Polyester Resin Having Aliphatic Diol Unit, Aliphatic Dicarboxylic Acid Unit, and Aromatic Dicarboxylic Acid Unit as Main Structural Units]
Component (A3) is, for example, an aliphatic diol unit represented by the above formula (1), an aliphatic dicarboxylic acid unit represented by the above formula (2), and the following formula (3). It contains an aromatic dicarboxylic acid unit as an essential component. Furthermore, it may have the aforementioned oxycarboxylic acid unit.

-OC-R ₃₁ -CO- (3)
[In formula (3), R ₃₁ represents a divalent aromatic hydrocarbon group, and when it is copolymerized, it is not limited to one type. ]

Regarding the aliphatic diol that gives the diol unit of the formula (1) and the aliphatic dicarboxylic acid component that gives the aliphatic dicarboxylic acid unit of the formula (2), the above [(A1) the aliphatic diol unit and the aliphatic dicarboxylic acid unit are mainly Aliphatic polyester-based resin possessed as a structural unit], and preferable ones are also the same.

The aromatic dicarboxylic acid component that gives the aromatic dicarboxylic acid unit of formula (3) is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and diphenyldicarboxylic acid. These may be acid anhydrides. In addition, derivatives of aromatic dicarboxylic acids include lower alkyl esters of these aromatic dicarboxylic acids. Among these, terephthalic acid, isophthalic acid, or lower alkyl (eg, alkyl having 1 to 4 carbon atoms) ester derivatives thereof are preferred. These may be used individually by 1 type, and may be used in mixture of 2 or more types. In particular, terephthalic acid and/or terephthalic acid methyl esters or mixtures containing terephthalic acid and/or terephthalic acid methyl esters and isophthalic acid and/or isophthalic acid methyl esters are preferred.

Specific examples of the aliphatic-aromatic polyester resin are preferably polybutylene alkylate terephthalate, more preferably polybutylene adipate terephthalate or polybutylene succinate terephthalate, and particularly preferably polybutylene adipate terephthalate.

In the present invention, (A) the aliphatic polyester resin may be used alone or in combination of two or more. For example, two or more aliphatic polyester resins having different diol units or dicarboxylic acid units may be mixed and used.

The content of component (A) is not particularly limited, but is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably, based on the total amount of the emulsion resin composition (or the total amount of the emulsion composition). It is 30% by mass or more. Also, it is preferably 50% by mass or less, more preferably 48% by mass or less, and even more preferably 46% by mass or less.

[(B) Cellulose Acetate Resin]
As the component (B), commonly used known cellulose acetate resins can be used. Specific examples include cellulose acetates such as diacetyl cellulose and triacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate, cellulose acetate phthalate, and cellulose acetate benzoate. These can be used alone or in combination of two or more. Among these, cellulose acetate butyrate is preferred.

Commercially available products of component (B) include, for example, CAB-551-0.01, CAB-551-0.2, CAB-553-0.4, CAB-531-1 and CAB-500 manufactured by EASTMAN CHEMICAL. -5, CAB-321-0.1, CAB-381-0.1, CAB-381-0.5, CAB-381-2, CAB-321-20, CAP-504-0.2, CAP-482 -0.5, CAP-482-20 and the like.

The weight average molecular weight (Mw) of component (B) is not particularly limited, but is usually 8,000 or more, preferably 10,000 or more, more preferably 15,000 or more. Also, it is usually 150,000 or less, preferably 100,000 or less, more preferably 70,000 or less.
The weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The acetylation degree of component (B) is not particularly limited, but is preferably 0.6% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more. Also, it is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.
The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose, and is determined by measuring and calculating the degree of acetylation according to ASTM: D-817-91 (test method for cellulose acetate, etc.). be.

The 6% viscosity of component (B) is not particularly limited, but is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, and even more preferably 30 mPa·s or more. Also, it is preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, and even more preferably 5,000 mPa·s or less.
The 6% viscosity is obtained by dissolving a cellulose acetate resin in a 95% aqueous solution of acetone to a concentration of 6 wt/vol% and measuring the flow-down time using an Ostwald viscometer.

The mass ratio [(B)/(A)] of component (B) to component (A) is preferably 0.05 to 0.5, more preferably 0.07 to 0.5, and even more preferably is 0.09 to 0.5, particularly preferably 0.1 to 0.4, and may be 0.15 to 0.3. If the content of component (B) is too low, the production of the emulsion composition tends to be difficult, and the resulting emulsion composition tends to be less stable.

The content of component (B) is not particularly limited, but is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 2% by mass or more, based on the total amount of the emulsion resin composition (or the total amount of the emulsion composition). It is preferably 3% by mass or more, particularly preferably 5% by mass or more. Also, it is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 15% by mass or less.

[(C) Dispersant]
As the dispersant (C), a commonly used known general dispersant can be used. Examples include water-soluble polymers and various surfactants. These may be used alone or in combination of two or more.

Examples of water-soluble polymers include, but are not limited to, polyvinyl alcohol-based resin (hereinafter referred to as "PVA-based resin"), methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, Cellulose derivatives such as aminomethylhydroxypropylcellulose and aminoethylhydroxypropylcellulose, starch, tragacanth, pectin, glue, alginic acid or its salts, gelatin, polyvinylpyrrolidone, polyacrylic acid or its salts, polymethacrylic acid or its salts, polyacrylamide, polymethacrylamide, copolymers of vinyl acetate with unsaturated acids such as maleic acid, maleic anhydride, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, etc.; Examples thereof include copolymers, copolymers of vinyl ether and the above-mentioned unsaturated acids, and salts of the above-mentioned copolymers.
Examples of surfactants include nonionic surfactants, cationic surfactants, and anionic surfactants. Specifically, but not limited to, for example, polyoxyethylene nonylphenyl ether, polyoxyethylene octyl nonyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkylallyl ether, polyoxyethylene sorbitan monolaurate, poly Oxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyalkylene alkyl ether phosphate monoethanolamine salt, polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, etc. and polyoxyethylene alkylamino ethers.
Among these, PVA-based resins are preferably used from the viewpoint of enhancing the stability of the emulsion composition.

[PVA-based resin]
Examples of PVA-based resins used in the present invention include unmodified PVA-based resins and modified PVA-based resins.

The unmodified PVA resin can be produced by saponifying a vinyl ester polymer obtained by polymerizing a vinyl ester compound.

Examples of such vinyl ester compounds include vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurate, vinyl versatate, vinyl palmitate, and vinyl stearate. vinyl acetate is preferred. The vinyl ester compounds may be used alone or in combination of two or more.

The modified PVA-based resin can be produced by copolymerizing the vinyl ester-based compound and an unsaturated monomer copolymerizable with the vinyl ester-based compound, followed by saponification.

Examples of the unsaturated monomer copolymerizable with the vinyl ester compound include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene and α-octadecene, 3-buten-1-ol, Hydroxy group-containing α-olefins such as 4-penten-1-ol and 5-hexene-1-ol and derivatives such as acylated products thereof; acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid , unsaturated acids such as undecylenic acid, salts thereof, monoesters, or dialkyl esters; amides such as diacetone acrylamide, acrylamide, and methacrylamide; olefin sulfonic acids such as ethylenesulfonic acid, allylsulfonic acid, and methallylsulfonic acid; Its salt etc. are mentioned. These can be used alone or in combination of two or more.

Further, the modified PVA-based resin has a primary hydroxyl group in the side chain, for example, the number of the primary hydroxyl group in the side chain is usually 1 to 5, preferably 1 to 2, particularly preferably 1. is mentioned. Furthermore, it is preferable that the modified PVA-based resin has a secondary hydroxyl group in addition to the primary hydroxyl group. Examples of such modified PVA-based resins include PVA-based resins having hydroxyalkyl groups in side chains and PVA-based resins having 1,2-diol structural units in side chains.

The average saponification degree of the PVA-based resin is preferably 70 mol% or more, more preferably 72 to 99 mol%, even more preferably 78 to 95 mol%, and particularly preferably 82 to 90 mol%. If the average degree of saponification is too small, the water resistance of the film obtained using the resin composition for emulsion tends to be lowered.

In particular, when an unmodified PVA resin is used as the PVA-based resin, the average degree of saponification is preferably 72 mol% or more, more preferably 75 to 99 mol%, and even more preferably 80 to 95. in mol %. If the average degree of saponification is too small, the water resistance of the film obtained using the resin composition for emulsion tends to be lowered.

Further, when a modified PVA-based resin is used as the PVA-based resin, its average saponification degree is preferably 72 mol% or more, more preferably 75 to 99 mol%, and even more preferably 80 to 95. in mol %. If the average degree of saponification is too small, the water resistance of the film obtained using the resin composition for emulsion tends to be lowered.

The average degree of saponification is measured according to JIS K 6726 3.5.

Further, the viscosity of a 4% by mass aqueous solution of the PVA-based resin at 20° C. is preferably 10 to 70 mPa·s, more preferably 15 to 45 mPa·s, and even more preferably 20 to 40 mPa·s. If the viscosity is too low, the emulsion composition tends to be less stable.

When an unmodified PVA resin is used as the PVA-based resin, the unmodified PVA resin preferably has a 4% by mass aqueous solution viscosity at 20° C. of 5 to 50 mPa s, more preferably 13 to 45 mPa s. Even more preferably, it is 17 to 40 mPa·s. If the viscosity is too low, the emulsion composition tends to be less stable.

Further, when a modified PVA-based resin is used as the PVA-based resin, the viscosity of the 4% by mass aqueous solution of the modified PVA-based resin at 20° C. is preferably 5 to 50 mPa·s, more preferably 13 to 40 mPa·s. s, still more preferably 17 to 30 mPa·s. If the viscosity is too low, the emulsion composition tends to be less stable.

The 4% by mass aqueous solution viscosity is measured according to JIS K 6726 3.11.2.

The average degree of polymerization of the PVA-based resin is preferably 50 to 5,000, more preferably 150 to 4,000, still more preferably 300 to 3,000.
The average degree of polymerization can be determined according to the method for calculating the average degree of polymerization described in JIS K 6726.

In the present invention, each of the PVA-based resins can be used alone, and unmodified PVA-based resins can be used together, modified PVA-based resins can be used together, and unmodified PVA-based resins and modified PVA-based resins can be used together. In addition, two or more different types having different average saponification degrees, viscosities, modified species, modified amounts, etc. can be used in combination.

The mass ratio of the content of the dispersant (C) to the total content of the components (A) and (B) [(C)/[(A)+(B)]] is not particularly limited, but is from 0.05 to 0.2 is preferred, more preferably 0.06 to 0.18, still more preferably 0.07 to 0.15, and particularly preferably 0.08 to 0.12. Outside this range, the stability of the emulsion composition tends to decrease.

The content of component (C) is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.5% by mass, based on the total amount of the emulsion resin composition (or the total amount of the emulsion composition). Above, more preferably 1% by mass or more, particularly preferably 3% by mass or more. Also, it is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 12% by mass or less, and particularly preferably 10% by mass or less. Outside this range, the stability of the emulsion composition tends to decrease.

[(D) dispersion medium]
(D) The dispersion medium is not particularly limited as long as it is a water-soluble component within the substance and concentration range that does not usually affect the stability of the emulsion composition, and any aqueous solution containing them may be used, such as water only, polysaccharides. Examples include an aqueous solution and an aqueous cellulose (CNF) solution, and if the amount is small, a water-soluble organic solvent may be used in combination. Organic solvents include, for example, methanol, ethanol, and acetone. Among these, water is most preferable as the dispersion medium.

The content of component (D) is not particularly limited, but is preferably 25% by mass or more, more preferably 35% by mass or more, and even more preferably, based on the total amount of the emulsion resin composition (or the total amount of the emulsion composition). It is 40% by mass or more. Also, it is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

In addition, when a dispersion medium is a combination of water and an organic solvent, the content of water relative to the total amount of the dispersion medium is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. . Among these, it is most preferable to use only water as the dispersion medium.

The mass ratio of the total content of components (A) and (B) to the content of component (D) [[(A) + (B)]/(D)] is not particularly limited, but is from 0.7 to It is preferably 1.3, more preferably 0.8 to 1.25, still more preferably 0.9 to 1.2.

[Other ingredients]
An example of the emulsion resin composition according to the embodiment of the present invention contains, in addition to the above-described components, components that are commonly used in emulsion resin compositions as other components within a range that does not impair the effects of the present invention ( for example, 10% by mass or less). Examples of such components include, but are not limited to, preservatives, antifungal agents, antibacterial agents, thermoplastic resins, various stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, antirust agents, curing agents, fillers, and the like.

[Resin composition for emulsion and method for producing emulsion composition]
As an example of the resin composition for emulsion and the method for producing the emulsion composition according to the embodiment of the present invention, a production method known in the art, such as a phase inversion emulsification method, can be adopted. For example, (A) a step of melt-kneading an aliphatic polyester-based resin and (B) a cellulose acetate-based resin, and (C) a dispersant and (D) a dispersion medium are added to the melt-kneaded composition. It is produced by a phase inversion emulsification process of adding and mixing.

Although the melting point of the composition obtained by the step of melt-kneading (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin is not particularly limited, for example, it is preferably 110° C. or less, more preferably 108° C. or less. , and more preferably 105° C. or less. When the melting point is within the above range, the production of the emulsion composition tends to be facilitated in the phase inversion emulsification step of mixing with the dispersion medium, and the stability of the obtained emulsion composition tends to be high. . Although the lower limit of the melting point is not particularly limited, it is, for example, about 70°C.

The melt flow rate (MFR) of the composition obtained by the step of melt-kneading (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin is 8 g/10 when measured at 190° C. and 2.16 kg. minutes or more, more preferably 9 g/10 minutes or more, still more preferably 10 g/10 minutes or more, particularly preferably 15 g/10 minutes or more, particularly preferably 20 g/10 minutes or more, and 150 g/10 minutes or more. minutes or less, more preferably 100 g/10 minutes or less, and even more preferably 80 g/10 minutes or less. When the melt flow rate (MFR) is within the above range, the production of the emulsion composition tends to be facilitated in the phase inversion emulsification step of mixing with the dispersion medium, and the stability of the obtained emulsion composition is improved. tend to be higher.

An example of a method for producing an emulsion composition according to an embodiment of the present invention is, specifically, to put (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin into a kneader, and if necessary, A solvent or the like is arbitrarily added and melted and kneaded under heating conditions, (C) dispersant such as PVA resin, and (D) dispersion medium such as water are added thereto, and these components are mixed and phase inversion emulsified. Manufactured by the method of The heating temperature is usually 40 to 250°C, preferably 60 to 200°C, more preferably 60 to 160°C, still more preferably 80 to 150°C. The heating time is usually 10 to 1,800 seconds, preferably 10 to 600 seconds, more preferably 20 to 180 seconds.

Examples of the kneader include extruders, homogenizers (high pressure), roll mills, kneaders, ink rolls, and Banbury mixers. Among these, from the viewpoint of productivity, an extruder is preferable, and a multi-screw extruder having two or more screws such as a twin-screw extruder is particularly preferable.

When manufacturing using an extruder, for example, (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin are continuously supplied from a hopper of the extruder or a supply port of another system and heated under heating conditions. After melt kneading, (C) dispersant such as PVA resin and (D) dispersion medium such as water are added from another supply port provided in the same extruder, and kneaded and dispersed to phase inversion emulsify, An exemplary emulsion composition according to embodiments of the present invention can be obtained by continuous extrusion through a die.

Further, for example, using pellets obtained by melt-kneading (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin under heating conditions using an extruder or the like, according to the embodiment of the present invention An example emulsion composition can also be obtained. Specifically, pellets of a composition containing (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin are continuously supplied from the hopper of an extruder and melt-kneaded under heating conditions to obtain a PVA-based resin. (C) dispersant such as resin and (D) dispersion medium such as water are added from another supply port provided in the same extruder, kneaded and dispersed, phase inversion emulsified, and then continuously extruded through a die. Thus, an example emulsion composition according to an embodiment of the present invention can be obtained.

[Emulsion resin composition and emulsion composition]
The emulsion resin composition of the present embodiment obtained as described above is a water-based emulsion resin composition, and is preferably an emulsion composition obtained from a water-based emulsion resin composition. An aqueous emulsion composition is one in which particulate matter is dispersed and emulsified in an aqueous solvent. Alternatively, it is an emulsion system in which an aqueous liquid such as an organic solvent is used as a dispersion medium (that is, a continuous phase). In the emulsion composition of the present embodiment, a mixed composition of (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin is a dispersoid, and these are dispersed in an aqueous solvent in an aqueous emulsion composition. be.

The emulsion composition of the present embodiment obtained as described above has excellent stability. The stability of the emulsion composition can be evaluated, for example, by the method described in Examples below. For example, the sedimentation rate measured by the method described in Examples below is preferably 10% or less, more preferably 8% or less, even more preferably 6% or less, and particularly preferably 3% or less.

The dispersed particle size of the dispersoid in the emulsion composition according to one example of the embodiment of the present invention is 10 µm or less, preferably 5 µm or less, more preferably 2.5 µm or less, and even more preferably 2 µm or less. Also, the lower limit is usually about 0.01 μm.
The dispersed particle diameter is the median diameter (d50) corresponding to a cumulative particle diameter distribution value of 50% on a volume basis. ) can be measured.

The resin composition for emulsion according to one example of the embodiment of the present invention is excellent in biodegradability because it contains (A) an aliphatic polyester resin and (B) a cellulose acetate resin. From the viewpoint of improving the properties, it is preferable to use (A) an aliphatic polyester-based resin, (B) a cellulose acetate-based resin, and (C) a component having biodegradability as a dispersant. It is more preferable to use a PVA-based resin as the dispersant.

[Use]
The emulsion resin composition according to an example of the embodiment of the present invention is not limited to the following, but is in the form of a molded article (film or the like) molded using the emulsion resin composition obtained by a known molding method. can be used as
Further, the resin composition for emulsion according to one example of the embodiment of the present invention can be used as, for example, adhesives, adhesives, modifiers thereof, coating agents, heat sealing agents, paints, primers for paints, inks, binders, etc. , paper, films, sheets, structural materials, building materials, automobile parts, electrical and electronic products, packaging materials, clothing, pharmaceuticals, cosmetics (shampoos, rinses, milky lotions, lotions, perfumes, etc.), agricultural compositions (pesticide emulsions etc.), health foods, foods, etc. Among them, cosmetics, agricultural compositions, paints, inks, or adhesives containing the resin composition for emulsion according to one example of the embodiment of the present invention are suitable.
In addition, the resin composition for emulsion according to one example of the embodiment of the present invention is suitably used as a coating agent for an object to be coated (object to be coated) from the viewpoint of being excellent in heat-sealing properties, film-forming properties, and the like. The heat-sealing property and film-forming property of the coating agent containing the emulsion resin composition can be evaluated, for example, by the methods described in Examples below.

The object to be coated with the emulsion resin composition according to one example of the embodiment of the present invention is not particularly limited, but for example, a paper substrate is preferable. Pattern paper, release paper, inkjet paper, carbon paper, non-carbon paper, base paper for paper cups, greaseproof paper, manila ball, white ball, paper board such as liner, general fine paper, medium quality paper, printing paper such as gravure paper, etc.・Medium- and low-grade paper, newsprint, etc. can be mentioned. For example, a laminate comprising a layer made of a paper substrate and a layer made of an emulsion resin composition coated on the paper substrate is also suitable.

The object to be coated is preferably a plastic substrate, and examples of the plastic substrate include polyethylene terephthalate (PET) resin, polypropylene (PP) resin [biaxially oriented polypropylene (OPP), non-axially oriented polypropylene (CPP)], nylon resins, various biodegradable resins, polyethylene (PE) resins [low density polyethylene (LDPE), high density polyethylene (HDPE)], and the like. For example, a laminate comprising a layer made of a plastic substrate and a layer made of an emulsion resin composition coated on the plastic substrate is also suitable.

The coating method using the emulsion resin composition according to one example of the embodiment of the present invention is not particularly limited, but examples include roll coating, dip coating, bar coating, nozzle coating, die coating, and spraying. A coating method, a spin coating method, a curtain coating method, a flow coating method, and the like can be mentioned.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, "parts" and "%" mean mass standards.

The following were prepared as (A) component, (B) component, and (C) component.
<(A) Component>
(a1) Polybutylene succinate [“BioPBS (FZ71PM)” manufactured by PTT MCC Biochem, melt flow rate (MFR) 22 g/10 min (190°C, 2.16 kg), melting point 115°C]
<(B) Component>
(b1) Cellulose acetate butyrate ["CAB-55 1-0.01" manufactured by EASTMAN CHEMICAL, acetylation degree 2% by mass, 6% viscosity 38 mPa s, weight average molecular weight 16,000]
<(C) Component>
(c1) PVA-based resin [unmodified PVA resin, average degree of polymerization 1,700, saponification degree 87-89%, 4% by mass aqueous solution viscosity at 20° C. 20.5-24.5 mPa s]

[Example 1]
Polybutylene succinate (a1) and cellulose acetate butyrate (b1) at a mass ratio of 80:20 (a1:b1), a twin-screw extruder [KZW15TW-60MG, manufactured by Technobell Co., L / D = 60] It was continuously fed from a hopper and melt-kneaded under conditions of 140°C to obtain a mixed composition having a melting point of 100°C and an MFR (190°C, 2.16 kg) of 62 g/10 min. While continuously supplying the PVA-based resin (c1) as a dispersant and water as a dispersion medium from the supply port, the mixture is continuously extruded under the conditions of a heating temperature (cylinder temperature) of 90 to 105 ° C. and a heating time of 180 seconds. (screw rotation speed: 300 rpm) and an emulsion composition having the mass ratio shown in Table 1 below was obtained.
The dispersed particle size (median size) in the emulsion composition was measured with a laser diffraction particle size measuring device (LA-950V2, manufactured by Horiba Ltd.) and found to be 1.3 μm.

[Example 2]
Polybutylene succinate (a1) and cellulose acetate butyrate (b1) were continuously supplied from the hopper of a twin-screw extruder at a mass ratio of 90:10 (a1:b1) and melt-kneaded to obtain a melting point of 103°C. , MFR (190° C., 2.16 kg) of 31 g/10 min.
The dispersed particle size (median size) in the emulsion composition was 1.7 μm.

[Comparative Example 1]
Polybutylene succinate (a1) was continuously supplied from the hopper of a twin-screw extruder [KZW15TW-60MG, manufactured by Technobel, L/D=60], and PVA as a dispersant was added from a supply port provided in the extruder. While continuously supplying the system resin (c1) and water as a dispersion medium, continuously extruding at a heating temperature (cylinder temperature) of 90 to 105 ° C. (screw rotation speed: 300 rpm), mass ratio described in Table 1 below A composition consisting of This composition was mixed with poorly dispersed polybutylene succinate (a1), resulting in separation of water and resin lumps, and an emulsion composition could not be obtained.

The emulsion compositions of Examples 1 and 2 were evaluated for emulsion performance as described below. First, the sedimentation rate was evaluated in order to evaluate the stability of the emulsion composition. In addition, in order to evaluate the coating performance of the emulsion composition, evaluation of the film-forming property and evaluation of the heat-sealing property of the coating layer were performed. The results are shown in Table 1 below. As described above, in Comparative Example 1, no emulsion composition was obtained, so the following evaluation was impossible.

[Emulsion composition stability test (sedimentation rate)]
The obtained emulsion composition was placed in a sedimentation tube (bottom area: 9.62 cm ² , height: 7.8 cm) and allowed to stand at 50°C for 4 weeks, after which the volume of the separated layer was visually evaluated. At that time, the sedimentation rate was calculated based on the reading of the scale of the sedimentation tube (the height of the separation layer). The sedimentation rate is calculated based on the following formula.
[Formula] Sedimentation rate = height of separation layer (cm)/height of total emulsion composition (cm) x 100

[Film-forming test]
The resulting emulsion composition was applied on a Teflon (registered trademark) sheet using an applicator with a clearance of 100 μm, dried at 80° C. for 10 minutes, and confirmed whether or not a film was formed. When the emulsion composition can be formed into a film, a cellophane adhesive tape (CT-18S, manufactured by Nichiban Co., Ltd.) is pasted on the formed coating film, and then the tape is peeled off to remove the coating film. Film formability was evaluated. Evaluation criteria are as follows.
(Evaluation criteria)
◯: Form a film. No cracks occur during peeling.
Δ: A film is formed. Cracks occur during delamination.
x: No film formation.

[Heat sealability test]
The resulting emulsion composition was coated on copy paper having a basis weight of 60 g/m ² with a bar coder and dried at 140° C. for 5 minutes. The resulting coated paper was cut into strips with a length of 15 cm and a width of 15 mm, the coated surfaces were superimposed, and heat-sealed under the conditions of 140° C., 1.25 kg/cm ² pressure, and 2 seconds for testing. A piece (coated paper) was obtained. Using this test piece, a 180° peel test was performed at a tensile speed of 100 mm/min using a tensile tester (AG-IS, manufactured by Shimadzu Corporation), and evaluation was made according to the following criteria.
(Evaluation criteria)
Good: The heat-sealed portion of the test piece did not peel off.
x: The heat-sealed portion of the test piece was peeled off.

As shown in Table 1, Examples 1 and 2, which are emulsion compositions containing (A) an aliphatic polyester-based resin and further contain (B) a cellulose acetate-based resin, were able to obtain emulsion compositions. Moreover, it is found that the stability of the emulsion composition and the coating performance (film-forming property and heat-sealing property) are excellent.

The emulsion resin composition and emulsion composition of the present invention are particularly useful as various coating agents, for example, coating agents for paper substrates, coating agents for plastic substrates, and the like.

Claims (19)

A resin composition for emulsion containing (A) an aliphatic polyester-based resin and (B) a cellulose acetate-based resin. The emulsion resin according to claim 1, wherein the mass ratio [(B)/(A)] of the (B) cellulose acetate resin to the (A) aliphatic polyester resin is 0.05 to 0.5. Composition. 3. The resin composition for emulsion according to claim 1, wherein the resin composition for emulsion has a melt flow rate of 8 g/10 minutes or more at 190[deg.] C. and 2.16 kg. 3. The resin composition for emulsion according to claim 1, wherein the cellulose acetate resin (B) contains cellulose acetate butyrate. 3. The emulsion resin composition according to claim 1, further comprising (C) a dispersant. 3. The resin composition for emulsion according to claim 1, which is a water-based resin composition for emulsion further containing water. An emulsion composition comprising the resin composition for emulsion according to claim 1 or 2. An emulsion composition containing the emulsion resin composition according to claim 5 . An emulsion composition comprising the emulsion resin composition according to claim 6 . A coating agent comprising the resin composition for emulsion according to claim 1 or 2. 11. The coating agent according to claim 10, wherein the object to be coated is a paper substrate. 11. The coating agent according to claim 10, wherein the object to be coated is a plastic substrate. A molded article obtained by using the resin composition for emulsion according to claim 1 or 2. A film using the resin composition for emulsion according to claim 1 or 2. A cosmetic containing the resin composition for emulsion according to claim 1 or 2. An agricultural composition comprising the resin composition for emulsion according to claim 1 or 2. A paint containing the resin composition for emulsion according to claim 1 or 2. An ink containing the resin composition for emulsion according to claim 1 or 2. A pressure-sensitive adhesive containing the resin composition for emulsion according to claim 1 or 2.