TW201429997A - Vinyl acetal polymer - Google Patents

Abstract

The purpose of the present invention is to provide a vinyl acetal polymer which has a low solution viscosity and excellent handleability, while exhibiting excellent solubility in alcohol-based solvents and the like and excellent bondability to inorganic materials such as glass. The present invention is a vinyl acetal polymer which is obtained by acetalizing a vinyl alcohol polymer, and which is characterized in that: the vinyl alcohol polymer contains a monomer unit having a group represented by formula (1) and satisfies formula (I); and the degree of acetalization is from 45% by mole to 80% by mole (inclusive). It is preferable that the vinyl alcohol polymer also satisfies formulae (II) and (III). 370 <= P S <= 6,000 (I) 200 <= P <= 4,000 (II) 0.1 <= S <= 10 (III) P: Viscosity-average degree of polymerization S: Rate of content of above-mentioned monomer unit (mol%)

Description

Ethylene acetal polymer

This invention relates to ethylene acetal polymers.

The ethylene acetal polymer represented by a vinyl butyral polymer is obtained by acetalizing a vinyl alcohol polymer (hereinafter sometimes abbreviated as "PVA"), and its toughness and film formation are obtained. It is excellent in dispersibility such as the nature, the added inorganic or organic powder, and the like. Therefore, the above ethylene acetal-based polymer can be used for an interlayer film, an ink, a paint, an enamel for glazing, a rust primer, a paint, a dispersant, an adhesive, a ceramic green sheet, and a thermal image for bonding glass. Various uses such as a sexy light material, an aqueous ink receiving layer adhesive, and the like.

In order to improve the adhesion to glass, ceramics or inorganic materials in addition to the above-mentioned properties of the above-mentioned ethylene acetal polymer, it is proposed to use an alkyl acetal polymer modified with a decyl group (hereinafter, In the meantime, it is simply referred to as "the acetal-containing ethylene acetal polymer" (see Japanese Patent Laid-Open Publication No. 2005-194409). However, the above-mentioned ethylene acetal polymer containing a decyl group has a very low solubility in an organic solvent such as an alcohol solvent, and even if it is dissolved, the viscosity of the solution is high, and there is a disadvantage that it is difficult to handle.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2005-194409

[Summary of the Invention]

The present invention is based on the above-mentioned problems, and an object thereof is to provide an ethylene acetal polymer which is excellent in solubility in an alcohol-based solvent or the like and adhesion to an inorganic substance such as glass, and has a low solution viscosity and excellent workability.

In order to solve the above problems, an ethylene acetal polymer obtained by acetalizing a vinyl alcohol polymer is characterized in that the vinyl alcohol polymer is contained. a monomer unit having a group represented by the following formula (1), and satisfying the following formula (I), the degree of acetalization being 45 mol% or more and 80 mol% or less;

(In the formula (1), R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ² is a group represented by an alkoxy group, a decyloxy group or OM; and M is a hydrogen atom, an alkali metal or an ammonium group; R ³ and R ⁴ are each independently a hydrogen atom or an alkyl group; the hydrogen atom of the alkyl group, the alkoxy group and the decyloxy group represented by R ¹ to R ⁴ may be replaced by a substituent containing an oxygen atom or a nitrogen atom; m is an integer of 0 to 2; n is an integer of 3 or more; in the case where R ¹ to R ⁴ exist as a complex number, each of R ¹ to R ^{4 in the} plural exists independently and satisfies the above definition); 370 ≦ P × S≦6,000...(I)

P: viscosity average degree of polymerization

S: content ratio (mol%) of the above monomer unit.

The ethylene acetal polymer is obtained by acetalizing PVA, and the PVA contains a monomer unit having a group represented by the above formula (1), and has an alkylene group via an alkyl group having 3 or more carbon atoms. The structure that is connected to the main chain. Therefore, the ethylene acetal polymer has sufficient solubility in an alcohol solvent or the like even if the quality of the decyl group is improved, and the viscosity of the solution can be lowered. Although the reasons for this effect have not been fully ascertained, they are presumed as follows. When the previously fluorinated alkyl group-containing PVA is acetalized by an acid, the stanol groups are subjected to a crosslinking reaction with each other during the acetalization, and as a result, the obtained ethylene acetal-based polymer is used for an alcohol-based solvent. Very low solubility. However, since the PVA has a structure in which an alkylene group is bonded to a main chain via an alkylene group defined by the present invention, it is presumed that the crosslinking reaction of the stanol groups with each other during the acetalization is suppressed. As a result, the ethylene acetal-based polymer obtained has a sufficient solubility in an alcohol-based solvent or the like and lowers the viscosity of the solution. In addition, the ethylene acetal polymer is improved in the above range by the product (P × S) of the viscosity average polymerization degree (P) of the PVA and the monomer unit content (S). The decyl group is a mass, and the characteristics derived from a decyl group, such as an inorganic substance such as glass, can be effectively exhibited. In addition, by setting the degree of acetalization to be 45 mol% or more and 80 mol% or less, the solubility of the ethylene acetal polymer to an alcohol solvent or the like can be improved.

Preferably, the PVA further satisfies the following formulas (II) and (III): 200≦P≦4,000...(II)

0.1≦S≦10...(III)

P: viscosity average degree of polymerization

S: content ratio (mol%) of the above monomer unit.

By setting the viscosity average degree of polymerization (P) of the PVA and the content ratio (S) of the monomer unit to the above range, the solubility of the ethylene acetal polymer to an alcohol solvent or the like can be obtained. And the adhesion with inorganic substances such as glass is improved, and the viscosity of the solution can be further lowered.

n in the above formula (1) is preferably an integer of 6 to 20. By setting the value of n to the above range, the crosslinking reaction between the stanol groups in the acetalization process can be further suppressed, and the solubility in an alcohol solvent or the like can be further improved, even at a high degree of polymerization. In other cases, the rate of modification of the alkylene group can also be increased.

The above monomer unit is preferably represented by the following formula (2):

(In the formula (2), R ¹ to R ⁴ , m and n have the same meanings as in the formula (1); X is a direct bond, a divalent hydrocarbon group, or a divalent organic group containing an oxygen atom or a nitrogen atom; R ⁵ Is a hydrogen atom or a methyl group).

Since the monomer unit has the structure represented by the above formula (2), the properties of the ethylene acetal polymer can be further improved.

X in the above formula (2) is preferably represented by the following formula (3): -CO-NR ⁶ -*...(3)

(In the formula (3), R ⁶ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; * means a bond to a group represented by the above formula (1)).

R ⁶ in the above formula (3) is a hydrogen atom, and n in the above formula (2) is preferably an integer of from 3 to 12. By setting the above monomer unit to such a structure, the solubility of the ethylene acetal polymer to an alcohol solvent or the like can be further improved, and the solution viscosity can be further lowered. Moreover, the manufacture of the above PVA can be easily performed.

The aldehyde used for acetalization is preferably at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, hexanal and benzaldehyde, and particularly preferably butyraldehyde. By using such an aldehyde, the acetalization of the above PVA can be efficiently performed.

As described above, the ethylene acetal polymer of the present invention is excellent in solubility in an alcohol solvent or the like and adhesion to an inorganic substance such as glass, and has a low solution viscosity and excellent handleability. Therefore, the ethylene acetal polymer is suitably used for the laminated film intermediate film composition, the slurry composition for the ceramic capacitor electrode paste, the ceramic green sheet slurry composition, and the ink composition. Various uses such as a coating composition, an adhesive composition, and a thermographic photosensitive material composition.

[Formation for implementing the invention] <ethylene acetal polymer>

The ethylene acetal polymer of the present invention is obtained by acetalizing PVA, and the PVA contains a monomer unit having a group represented by the above formula (1), and has an alkylene group via a carbon number of 3 or more. The structure of the base and the main chain. Therefore, the ethylene acetal polymer has sufficient solubility in an alcohol solvent or the like even if the quality of the decyl group is improved, and the viscosity of the solution can be lowered. Although the reasons for this effect have not been fully ascertained, they are presumed as follows. When the former PVA containing a decyl group is acetalized by an acid, the stanol groups are subjected to a crosslinking reaction with each other during the acetalization, and as a result, the obtained ethylene acetal polymer is an alcohol solvent. Very low solubility. However, since the PVA has a structure in which an alkylene group is bonded to a main chain via an alkylene group defined by the present invention, it is presumed that the crosslinking reaction of the stanol groups with each other during the acetalization is suppressed. As a result, the ethylene acetal-based polymer obtained has a sufficient solubility in an alcohol-based solvent or the like and lowers the viscosity of the solution. In addition, the ethylene acetal polymer is improved in the above range by the product (P × S) of the viscosity average polymerization degree (P) of the PVA and the monomer unit content (S). The decyl group is a mass, and the characteristics derived from a decyl group, such as an inorganic substance such as glass, can be effectively exhibited. In addition, by setting the degree of acetalization to be 45 mol% or more and 80 mol% or less, the solubility of the ethylene acetal polymer to an alcohol solvent or the like can be improved.

<PVA>

The above PVA contains a monomer unit having a group represented by the above formula (1). That is, the PVA described above includes a copolymer of a monomer unit having a group represented by the above formula (1) and a vinyl alcohol unit (-CH ₂ -CHOH-), and may further have other monomer units.

In the above formula (1), R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of the above alkyl group include a methyl group, an ethyl group, a propyl group and the like.

R ² is a group represented by an alkoxy group, a decyloxy group or OM. M is a hydrogen atom, an alkali metal or an ammonium group ( ⁺ NH ₄ ). The alkoxy group may, for example, be a methoxy group or an ethoxy group. Examples of the above methoxy group include an ethoxy group, a propenyloxy group and the like. Examples of the alkali metal include sodium, potassium, and the like. Among the groups represented by R ² , a group represented by an alkoxy group or OM, more preferably an alkoxy group having 1 to 5 carbon atoms, and an OM represented by M being a hydrogen atom or an alkali metal are used. Further, it is more preferably a group represented by methoxy, ethoxy, and M which is sodium or potassium OM.

R ³ and R ⁴ are each independently a hydrogen atom or an alkyl group. Examples of the alkyl group include the above-mentioned alkyl groups having 1 to 5 carbon atoms. In the case of R ³ and R ⁴ , a hydrogen atom or a methyl group is preferred.

The hydrogen atom of the alkyl group, the alkoxy group and the decyloxy group represented by R ¹ to R ⁴ may be replaced by a substituent containing an oxygen atom or a nitrogen atom. Examples of the substituent containing an oxygen atom include an alkoxy group, a decyloxy group and the like. Further, examples of the substituent containing a nitrogen atom include an amine group, a cyano group and the like.

Further, in the case where R ¹ to R ⁴ are respectively present in plural, each of R ¹ to R ^{4 in the} plural plural satisfies the above definition independently.

m is an integer from 0 to 2, but is preferably 0. m is 0, that is, the above monomer unit has an effect of further increasing the decyl group by having three R ² groups.

n is an integer of 3 or more. When PVA having n of less than 3 is not added to the basic compound, it is difficult to dissolve in the water of the acetalization solvent, and acetalization in the acidic aqueous solution cannot be performed. The upper limit of n is not particularly limited, but is preferably 20, more preferably 15, and still more preferably 12. With respect to the lower limit of n, it is preferably 4, more preferably 6, and still more preferably 8. The ethylene acetal polymer of the present invention produced from such a PVA has a mercaptoalkyl group having a carbon number of 3 or more, that is, an alkyl group having n of 3 or more in the above formula (1) is bonded to the main chain. The PVA of the structure is obtained by acetalization, and even if the quality of the decyl group is improved, it has sufficient solubility to an alcohol-based solvent or the like, and the viscosity of the solution can be lowered. Although the reasons for this effect have not been fully ascertained, they are presumed as follows. When the previously fluorinated alkyl group-containing PVA is acetalized by an acid, the stanol groups are subjected to a crosslinking reaction with each other during the acetalization, and as a result, the obtained ethylene acetal-based polymer is used for an alcohol-based solvent. Very low solubility. However, since the PVA has a structure in which an alkylene group is bonded to a main chain via an alkylene group defined by the present invention, it is presumed that the crosslinking reaction of the stanol groups with each other during the acetalization is suppressed. As a result, the ethylene acetal-based polymer obtained has a sufficient solubility in an alcohol-based solvent or the like and lowers the viscosity of the solution.

The specific structure of the monomer unit is not particularly limited as long as it has the group represented by the above formula (1), but is preferably represented by the above formula (2).

In the formula (2), the definitions of R ¹ to R ⁴ , m and n are the same as those in the formula (1). Again, the preferred base or range of values is the same.

X is a direct bond, a divalent hydrocarbon group or a divalent organic group containing an oxygen atom or a nitrogen atom. By having the above-described monomer unit having the structure represented by the above formula (2), the properties of the ethylene acetal polymer can be further improved.

Examples of the above-mentioned divalent hydrocarbon group include a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms and a divalent aromatic hydrocarbon group having 6 to 10 carbon atoms. Examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms include a methylene group, an exoethyl group, and a propyl group. Examples of the above-mentioned divalent aromatic hydrocarbon group having 6 to 10 carbon atoms include a stretching phenyl group and the like. Examples of the divalent organic group containing an oxygen atom include an ether group, an ester group, a carbonyl group, a decylamino group, and a group in which these groups are bonded to a divalent hydrocarbon group. Examples of the divalent organic group containing a nitrogen atom include an imido group, a guanamine group, and a group in which these groups are bonded to a divalent hydrocarbon group.

Among the groups represented by the above X, a divalent organic group containing an oxygen atom or a nitrogen atom is preferred, and a group containing a guanamine group is more preferred, and further preferably -CO-NR ⁶ -* (R ⁶ is A hydrogen atom or an alkyl group having 1 to 5 carbon atoms; * represents a group represented by a bond with a group represented by the above formula (1). Thus, the monomer unit has a polar structure at a position apart from the decyl group, preferably a guanamine structure, and can maintain both the properties from the decyl group and the ethylene acetal polymer. The solubility in an alcohol-based solvent or the like is further improved, and the monomer is easily obtained, and the viscosity of the solution can be further lowered. Further, in the case of the above R ⁶ , a hydrogen atom is preferred from the viewpoint of further improving the above function or facilitating the production of the PVA described above.

R ⁵ is a hydrogen atom or a methyl group.

The monomer unit is more preferably further represented by the following formula (4).

In the formula (4), the definitions of R ¹ , R ² , R ⁵ , X and m are the same as those in the above formula (2). Again, the preferred base or range of values is the same.

In the above formula (4), R ³ ' and R ⁴ ' are each independently a hydrogen atom or an alkyl group. Examples of the alkyl group include the above-mentioned alkyl groups having 1 to 5 carbon atoms. In the case of R ³ 'and R ⁴ ', a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred. The hydrogen atom of the alkyl group represented by R ³ 'and R ⁴ ' may be replaced by a substituent containing an oxygen atom or a nitrogen atom. Examples of the substituent containing an oxygen atom include an alkoxy group, a decyloxy group and the like. Further, examples of the substituent containing a nitrogen atom include an amine group, a cyano group and the like. Further, in the case where R ³ ' and R ⁴ ' are respectively present in plural, each of R ³ ' and R ⁴ ' in the plural plural satisfies the above definition independently.

In the above formula (4), n' is an integer of 1 or more. The upper limit of n' is not particularly limited, but is preferably 18, more preferably 13, and still more preferably 10. With respect to the lower limit of n', it is preferably 2, more preferably 4, still more preferably 6.

When the monomer unit is represented by the above formula (4), the functions of the ethylene acetal polymer can be more effectively expressed.

The above PVA satisfies the following formula (I): 370 ≦ P × S ≦ 6,000 (I)

P: viscosity average degree of polymerization

S: content ratio of the above monomer unit (% by mole)

The above viscosity average degree of polymerization (P) is measured in accordance with JIS-K6726. That is, in the case where the degree of saponification is less than 99.5 mol%, the PVA is further saponified to a degree of saponification of 99.5 mol% or more, and after the refining, the ultimate viscosity [η] which can be measured from water at 30 ° C (unit) : deciliter / g) is obtained by the following formula: P = ([η] × 1000 / 8.29) ^(1/0.62)

Further, the viscosity average degree of polymerization of the ethylene acetal polymer can be determined from the viscosity average degree of polymerization P of the above PVA used in the production. That is, since the degree of polymerization is not changed by acetalization described later, the average degree of polymerization of the PVA is the same as the average degree of polymerization of the ethylene acetal polymer obtained by acetalization.

The content ratio (S: mol%) of the above monomer unit was determined from proton NMR of a vinyl ester polymer before saponification. In the case where the proton NMR of the vinyl ester polymer before saponification is measured, the vinyl ester polymer is reprecipitated by hexane-acetone to be purified, and the unreacted monomer having a decyl group is sufficiently removed from the polymer. Then, it was dried under reduced pressure at 90 ° C for 2 days, and then dissolved in a solvent of CDCl ₃ for analysis.

Further, the content ratio (S: mol %) of the monomer unit of the ethylene acetal polymer is determined from the content ratio (S: mol%) of the monomer unit of the PVA used for production. Got it. That is, because The content of the monomer unit is not changed by acetalization described later, and the content of the monomer unit of the PVA and the single sheet of the ethylene acetal polymer obtained by acetalizing the same The content of the body unit is the same.

The product (P × S) of the viscosity average degree of polymerization (P) and the content ratio (S) of the above monomer unit corresponds to the number (average value) of the above monomer units per 100 molecules. When the product (P × S) is less than the above lower limit, the properties derived from the fluorenyl group such as the adhesion to the inorganic material such as glass which the ethylene acetal polymer has can not be sufficiently exhibited. On the other hand, when the product (P × S) exceeds the above upper limit, the solubility in an alcohol solvent or the like is lowered. The product (P × S) preferably satisfies the following formula (I'), and more preferably satisfies the following formula (I"): 400 ≦ P × S ≦ 3,000 (I')

500≦P×S≦2,000...(I”).

Preferably, the PVA further satisfies the following formulas (II) and (III): 200≦P≦4,000...(II)

0.1≦S≦10...(III)

P: viscosity average degree of polymerization

S: content ratio (mol%) of the above monomer unit.

By setting the viscosity average degree of polymerization (P) and the content ratio (S) of the monomer unit to the above range, the solubility of the ethylene acetal polymer to an alcohol solvent or the like can be obtained and the glass can be used. The adhesion of the inorganic substance is further improved, and the viscosity of the solution can be further lowered.

Further, it is more preferable that the viscosity average degree of polymerization (P) satisfies the following formula (II'), and more preferably satisfies the following formula (II"). 500≦P≦3,000...(II’)

1,000≦P≦2,400...(II”).

When the viscosity average degree of polymerization (P) is less than the above lower limit, the effect derived from an alkyl group such as adhesion to an inorganic substance such as glass may be lowered. On the other hand, when the viscosity average degree of polymerization (P) exceeds the above upper limit, the solubility of the ethylene acetal polymer to an alcohol solvent or the like and adhesion to an inorganic substance such as glass may be lowered.

Further, the content of the monomer unit more preferably satisfies the following formula (III'), and more preferably satisfies the following formula (III"), 0.25 ≦ S ≦ 6 (III')

0.5≦S≦5...(III”).

When the content ratio (S) of the monomer unit is less than the above lower limit, the effect of the alkyl group such as glass may be lowered by the effect of the alkyl group. On the other hand, when the content ratio (S) of the monomer unit exceeds the above upper limit, the solubility of the ethylene acetal polymer to an alcohol solvent or the like and the adhesion to an inorganic material such as glass may be lowered.

The degree of saponification of the PVA is not particularly limited, but is preferably 80% by mole or more, more preferably 90% by mole or more, still more preferably 95% by mole or more, and particularly preferably 97% by mole. the above. When the degree of saponification of the PVA is less than the above lower limit, the effect of the alkyl group on the adhesion of glass, ceramics, and inorganic substances may be lowered. In addition, the upper limit of the degree of saponification of the PVA is not particularly limited, but is, for example, 99.9 mol% in consideration of productivity and the like. The degree of saponification of the PVA herein means a value measured in accordance with the method described in JIS-K6726.

<Method of Manufacturing PVA>

The method for producing the PVA is not particularly limited, and the obtained copolymer can be obtained by, for example, copolymerizing a vinyl ester monomer with a monomer having a group represented by the above formula (1). (Vinyl ester polymer) is obtained by saponification.

Examples of the vinyl ester-based monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl phthalate, vinyl laurate, vinyl stearate, and benzoic acid. Vinyl ester, trimethyl vinyl acetate, vinyl versatate, and the like. Among these, vinyl acetate is preferred.

Further, when the monomer having the group represented by the above formula (1) is copolymerized with the vinyl ester monomer, the purpose of adjusting the viscosity average degree of polymerization (P) of the obtained PVA is as long as it is not impaired. Within the scope of the present invention, the polymerization can be carried out in the presence of a chain transfer agent. Examples of the chain transfer agent include aldehydes such as acetaldehyde and propionaldehyde; ketones such as acetone and methyl ethyl ketone; 3-mercaptopropyltrimethoxydecane and 3-mercaptopropyltriethoxydecane; Mercaptans such as 2-hydroxyethanethiol, n-dodecylmercaptan, mercaptoacetic acid, 3-mercaptopropionic acid; halogenated hydrocarbons such as tetrachloromethane, bromotrichloromethane, trichloroethylene, and perchloroethylene.

The monomer having a group represented by the above formula (1) may, for example, be a compound represented by the following formula (5). By using the compound represented by the following formula (5), PVA containing a monomer unit having a group represented by the above formula (2) can be finally obtained easily.

In the formula (5), the definitions of R ¹ to R ⁵ , X, m and n are the same as those in the formula (2). Again, the preferred base or range of values is the same.

The compound represented by the above formula (5) may, for example, be 3-(meth)acrylamide-propyltrimethoxydecane, 4-(meth)acrylamide-butyltrimethoxydecane, 6 - (Meth) acrylamide hexyl methoxy decane, 8-(meth) propylene decyl octyl trimethoxy decane, 12-(meth) acrylamide decyl trimethoxy decane, 18-( Methyl) acrylamide octadecyltrimethoxy decane, 3-(methyl) propylene decyl propyl triethoxy decane, 3-(methyl) acrylamidopropyl tributoxy decane, 3- (Methyl) acrylamide propyl methyl dimethoxy decane, 3-(methyl) propylene decyl propyl dimethyl methoxy decane, 3-(methyl) propylene phthalamide-3-methyl Butyltrimethoxydecane, 4-(methyl)propenylamine-4-methylbutyltrimethoxydecane, 4-(methyl)propenylamine-3-methylbutyltrimethoxydecane, 5 - (Meth) acrylamide-5-methylhexyltrimethoxydecane, 4-pentenyltrimethoxydecane, 5-hexenyltrimethoxydecane, and the like.

The method of copolymerizing the vinyl ester monomer and the monomer having the group represented by the above formula (1) includes a bulk polymerization method, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, and the like. method. In particular, in the case where the polymerization temperature is lower than 30 ° C, an emulsion polymerization method is preferred. When the polymerization temperature is 30 ° C or higher, a bulk polymerization method which is carried out without a solvent or a solution polymerization method using a solvent such as an alcohol is usually employed.

In the case of the emulsion polymerization method, water may be used, and a lower alcohol such as methanol or ethanol may be used in combination. Further, as the emulsifier, a known emulsifier can be used. As the initiator in the case of copolymerization, a redox-based initiator which uses an iron ion-oxidant-reducing agent in combination is preferably used for the controlled polymerization. In the case of the bulk polymerization method or the solution polymerization method, when the copolymerization reaction is carried out, the manner of the reaction can be carried out in any of a batch type and a continuous type. When the copolymerization reaction is carried out by a solution polymerization method, the alcohol used as the solvent may, for example, be a lower alcohol such as methanol, ethanol or propanol. The initiator used in the copolymerization reaction in this case may, for example, be 2,2'-azobisisobutyronitrile or 2,2'-azobis(2,4-dimethylvaleronitrile). , 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(N-butyl-2-methylpropionamide) and other azo initiators A known initiator such as a peroxide-based initiator such as benzamidine peroxide or n-propyl peroxycarbonate. The polymerization temperature at the time of carrying out the copolymerization reaction is not particularly limited, but is preferably in the range of 5 ° C to 70 ° C.

In the case of this copolymerization reaction, the copolymerizable monomers may be copolymerized as needed, as long as the scope of the present invention is not impaired. Examples of such a monomer include α-olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-hexene; fumaric acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, and the like. a carboxylic acid or a derivative thereof; an acrylate such as acrylic acid or a salt thereof, methyl acrylate, ethyl acrylate, n-propyl acrylate or isopropyl acrylate; methacrylic acid or a salt thereof, methyl methacrylate, methacrylic acid Ethyl ester, n-propyl methacrylate, isopropyl methacrylate Ethylene methacrylates; acrylamide derivatives such as acrylamide, N-methyl acrylamide, N-ethyl acrylamide; methacrylamide, N-methyl methacrylamide, N a methacrylamide derivative such as ethyl methacrylamide; a vinyl ether such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether or n-butyl vinyl ether (vinyl ether) Class; ethylene glycol ethers such as ethylene glycol vinyl ether, 1,3-propanediol vinyl ether, 1,4-butanediol vinyl ether, etc.; allyl acetate; propyl allyl ether, butyl allylate Allyl ethers such as ethers and hexyl allyl ethers; monomers having an oxygen alkyl group; isopropenyl acetate; 3-buten-1-ol, 4-penten-1-ol, 5-hexyl a hydroxyl group-containing α-olefin such as alken-1-ol, 7-octene-1-ol, 9-nonen-1-ol, 3-methyl-3-buten-1-ol; vinyl sulfonic acid a monomer having a sulfonic acid group such as allylsulfonic acid, methallylsulfonic acid or 2-propenylamine-2-methylpropanesulfonic acid; vinyloxyethyltrimethylammonium chloride, chlorine Vinyloxybutyltrimethylammonium, vinyloxyethyldimethylamine, vinyloxymethyldiethyl Amine, N-propylene decylamine methyltrimethylammonium chloride, N-propylene decylamine ethyltrimethylammonium chloride, N-propyleneamine dimethylamine, allyltrimethylammonium chloride, A monomer having a cationic group such as methallyltrimethylammonium chloride, dimethylallylamine or allylethylamine. The amount of the monomers to be used varies depending on the purpose or use of the monomers to be used, and the ratio based on all the monomers used for the copolymerization is usually 20 mol% or less, preferably 10 mol. Less than the ear.

The vinyl ester polymer obtained by the above copolymerization is then saponified in a solvent in accordance with a known method to form PVA.

In the case of the catalyst for the saponification reaction, a basic substance is usually used, and examples thereof include hydrogen of an alkali metal such as potassium hydroxide or sodium hydroxide. An alkali metal alkoxide such as an oxide or sodium methoxide. The amount of the basic substance used is preferably in the range of 0.004 to 0.5, more preferably in the range of 0.005 to 0.05, based on the vinyl ester monomer unit in the vinyl ester polymer. . Further, the catalyst may be added at the beginning of the saponification reaction, or a part of the catalyst may be added at the beginning of the saponification reaction, and the remainder may be added during the saponification reaction.

Examples of the solvent which can be used in the saponification reaction include methanol, methyl acetate, dimethyl hydrazine, diethyl hydrazine, dimethylformamide, and the like. Preferred among these solvents is methanol. Further, when methanol is used, the water content in methanol is preferably adjusted to preferably 0.001 to 1% by mass, more preferably 0.003 to 0.9% by mass, particularly preferably 0.005 to 0.8% by mass.

The saponification reaction is preferably carried out at a temperature of from 5 ° C to 80 ° C, more preferably from 20 ° C to 70 ° C. The time required for the saponification reaction is preferably from 5 minutes to 10 hours, more preferably from 10 minutes to 5 hours. The saponification reaction can be carried out in any of a batch method and a continuous method. After the completion of the saponification reaction, the remaining saponification catalyst may be neutralized as needed. Examples of the neutralizing agent include organic acids such as acetic acid and lactic acid, and ester compounds such as methyl acetate.

The PVA obtained by the saponification reaction can be washed as needed. The washing liquid used for the washing may, for example, be a low-carbon alcohol such as methanol or a low-carbon fatty acid ester such as methyl acetate, or a mixture thereof. A small amount of water, alkali or acid may be added to these washing liquids.

The pH of the aqueous solution containing the PVA at a concentration of 8 mass% is preferably 4 or more and 8 or less, more preferably 4.5 or more and 7 or less, and still more preferably 5 or more and 6.5. the following. Since the PVA is excellent in solubility in water, a uniform aqueous solution can be obtained even if an alkali or an acid such as sodium hydroxide is not added to water. As a result, the ethylene acetal polymer can be easily obtained from the above PVA.

<Manufacture of ethylene acetal polymer>

The ethylene acetal polymer of the present invention is obtained by acetalizing a PVA obtained as described above by a conventionally known method. The degree of acetalization at this time must be 45 mol% or more and 80 mol% or less. By setting the degree of acetalization to the above range, the ethylene acetal polymer can sufficiently exhibit properties derived from an alkylene group, and can improve solubility in an alcohol solvent or the like. The degree of acetalization of the ethylene acetal polymer is preferably 55 mol% or more and 80 mol% or less, more preferably 60 mol% or more and 80 mol% or less. When the degree of acetalization of the ethylene acetal polymer is adjusted, the amount of aldehyde added to the PVA to be used, the reaction time after addition of the aldehyde and the acid catalyst, and the like may be appropriately adjusted.

Here, the degree of acetalization of the ethylene acetal polymer indicates the ratio of the acetalized vinyl alcohol unit to the all monomer unit constituting the ethylene acetal polymer. The above degree of acetalization can be measured according to, for example, the method of JIS K6728 (1977).

In the method of acetalizing the PVA, for example, (1) the PVA is heated and dissolved in water to prepare an aqueous solution having a concentration of 5 to 30% by mass, and is cooled to 5 to 50° C., and then added. a method of preparing a quantity of aldehyde, cooling to -10 ° C to 30 ° C, and starting the acetalization by adding an acid to adjust the pH of the aqueous solution to 1 or less; (2) heating and dissolving the PVA in water to prepare a concentration of 5~30% by mass of an aqueous solution, which is cooled to 5 ° C to 50 ° C, and the pH of the aqueous solution is 1 or less by adding an acid. A method of cooling to -10 ° C to 30 ° C and adding a predetermined amount of aldehyde to start acetalization.

Examples of the aldehyde used for acetalization include formaldehyde (including paraformaldehyde), acetaldehyde (including polyacetaldehyde), propionaldehyde, butyraldehyde, isobutyraldehyde, 2-ethylbutyraldehyde, An aliphatic aldehyde such as n-pentanal, trimethylacetaldehyde, valeraldehyde, hexanal, heptaldehyde, 2-ethylhexanal, octanal, furfural, mercapto aldehyde or dodecyl aldehyde; cyclopentanal, A An alicyclic aldehyde such as cyclopentanal, dimethylcyclopentanal, cyclohexanal, methylcyclohexanal, dimethylcyclohexanal or cyclohexaneacetaldehyde; cyclopentenal, cyclohexenal, etc. Cyclic unsaturated aldehyde; benzaldehyde, 2-methylbenzaldehyde, 3-methylbenzylaldehyde, 4-methylbenzaldehyde, dimethylbenzylaldehyde, methoxybenzaldehyde, phenylacetaldehyde, β-benzene An aldehyde containing an aromatic or unsaturated bond, such as propionaldehyde, p-isopropylbenzaldehyde, naphthaldehyde, hydrazine formaldehyde, cinnamaldehyde, crotonaldehyde, acrolein, 7-octene-1-aldehyde; furfural, methylfurfural And other heterocyclic aldehydes.

Among these, at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, hexanal, and benzaldehyde is preferable, and butyraldehyde is particularly preferable. By using such an aldehyde, the acetalization of the above PVA can be performed more efficiently.

Further, an aldehyde having a functional group such as a hydroxyl group, a carboxyl group, a sulfonic acid group or a phosphoric acid group can also be used insofar as it does not impair the effects of the present invention.

The acid used for acetalization is not particularly limited, and examples thereof include acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid. Among these, hydrochloric acid, sulfuric acid, and nitric acid are preferable, and hydrochloric acid and nitric acid are more preferable, and two or more types may be used together. Moreover, in terms of the time required for the acetalization reaction, usually about 1 hour to 10 hours, the reaction is relatively Better than stirring. Further, in the case where acetalization is carried out under the above-described temperature conditions, when the degree of acetalization of the ethylene acetal polymer is not increased, the reaction can be continued at a high temperature of about 50 to 80 °C.

The granulated reaction product obtained by acetalization is separated by filtration, washed thoroughly with water, and a neutralizing agent such as an alkali is added thereto, washed, and dried to obtain an intended ethylene acetal polymer. Examples of the alkali compound used as the neutralizing agent include sodium hydroxide, potassium hydroxide and the like.

The ethylene acetal polymer of the present invention produced in this manner is excellent in solubility in an alcohol solvent or the like and adhesion to an inorganic substance such as glass, and the solution viscosity is lowered, and the workability is excellent. Therefore, the ethylene acetal polymer of the present invention is suitably used for laminating an interlayer film composition for glass, a slurry composition for a paste for a ceramic capacitor electrode, a slurry composition for a ceramic green sheet, and an ink composition. Various uses such as a coating composition, an adhesive composition, and a thermographic photosensitive material composition.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples. In the following examples and comparative examples, the parts and % represent the parts by mass and the mass%, respectively, unless otherwise stated.

Further, the monomer having a decylalkyl group (monomer A) used in the examples and the comparative examples was as follows: MAmPTMS: 3-methacrylamidopropyltrimethoxydecane

MAmOTMS: 8-methylpropenylamine octyltrimethoxydecane

VMS: vinyl trimethoxy decane

[Synthesis of PVA containing a decyl group]

PVA is produced by the following method, and the saponification degree and the content (S) of the monomer unit having the group represented by the above formula (1) are determined (in some examples, the content of the monomer unit having a decyl group) Rate), viscosity average degree of polymerization (P).

[Analysis method of PVA]

The analysis of PVA is carried out in accordance with the method described in JIS-K6726 unless otherwise stated.

[Manufacturing Example 1] Production of PVA1

In a 6 L separable flask equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, a co-monomer inlet, and an initiator addition port, 1,500 g of vinyl acetate, 500 g of methanol, and the above formula (1) were placed. A 1.87 g of MAmPTMS of the monomer (monomer A) shown, while nitrogen was bubbled through for nitrogen substitution in the system for 30 minutes. Further, MAmPTMS was dissolved in methanol to prepare a 8% monomer solution as a retardation solution, and nitrogen substitution was carried out by bubbling nitrogen gas. The temperature rise of the reactor was started, and when the internal temperature became 60 ° C, 0.8 g of 2,2'-azobisisobutyronitrile (AIBN) was added to initiate polymerization. The monomer solution (the ratio of vinyl acetate to monomer A (MAmPTMS)) in the polymerization solution was made constant while the delayed solution was dropped, and after polymerization at 60 ° C for 2.7 hours, the polymerization was stopped and the polymerization was stopped. The total amount of the comonomer solution (sequential addition liquid) added until the polymerization was stopped was 99 g. Further, the solid content concentration at the time of stopping the polymerization was 29.0%. Next, while adding methanol at a reduced pressure at 30 ° C, the unreacted vinyl acetate monomer was removed to obtain a methanol containing 40% of polyvinyl acetate (PVAc) having a group represented by the above formula (1). Dissolve liquid. Further, methanol and a methanol solution containing 10% by mass of sodium hydroxide were added thereto in this order under stirring so that the molar ratio of sodium hydroxide to the vinyl acetate unit in PVAc became 0.04, a solid of PVAc. The concentration of the component was 30% by mass, and the saponification reaction was started at 40 °C. After the addition of the alkali solution, a gel was formed in about 5 minutes. The gel was pulverized by a pulverizer, left at 40 ° C for 1 hour to carry out saponification, and then methyl acetate was added to neutralize the remaining base. After confirming the completion of the neutralization using a phenolphthalein indicator, a white solid was obtained by filtration, and methanol was added thereto, and the mixture was allowed to stand at room temperature for 3 hours and washed. After repeating the above-described washing operation three times, the liquid was removed by centrifugation, and the obtained white solid was allowed to stand in a dryer at 65 ° C for 2 days to obtain PVA 1 having a group represented by the above formula (1). The viscosity average degree of polymerization (P) of PVA1 was 1,700, and the degree of saponification was 98.6 mol%.

The content ratio of the monomer unit having a group represented by the above formula (1) (the content ratio of the monomer unit having a decyl group) of the obtained PVA1 was determined from the proton NMR of PVAc of the PVA precursor. Specifically, the reprecipitation of the obtained PVAc was carried out three times or more in n-hexane/acetone, and then dried under reduced pressure at 50° C. for 2 days to prepare PVAc for analysis. This PVAc was dissolved in CDCl ₃ and measured at room temperature using a 500 MHz proton NMR (JEOL GX-500). The peak α (4.7 to 5.2 ppm) derived from the main chain methine of the vinyl acetate unit and the peak β (3.4 to 3.8 ppm) of the methyl group derived from the methoxy group of the monomer A unit were calculated by the following formula. The content (S) of the monomer unit of the group represented by the formula (1). In PVA1, the content ratio (S) was 0.5 mol%. The results of the analysis regarding the obtained PVA are shown in Table 1.

The content ratio of the monomer unit having a group represented by the formula (1) (S: mol %) = {(peak area of β / 9) / (peak area of α + (peak area of β / 9))} ×100

[Production Examples 2 and 3 and Comparative Production Examples 1 to 3] Production of PVA2 to PVA6

The polymerization conditions such as the amount of vinyl acetate and methanol, the type and amount of monomer A, and the like, the concentration of PVAc in the saponification, and the molar amount of sodium hydroxide relative to the vinyl acetate unit were changed as shown in Table 1. PVA2~PVA6 was obtained in the same manner as in Production Example 1 except for the saponification conditions. The results of analysis of each PVA obtained are shown in Table 1. Further, in Table 1, the content ratio (S) of Production Examples 1 to 3 was compared, and the content ratio of the monomer unit having a decyl group other than the monomer unit having the group represented by the formula (1) was also included.

<Synthesis of ethylene acetal polymer> [Example 1] Synthesis of VAP1

480 g of PVA1 was placed in 5,520 mL of water, and while stirring, the temperature of the solution was raised to 90 ° C to dissolve it, and then cooled to 30 ° C, and the pH of the aqueous solution was measured. The pH of the measured aqueous solution is shown in Table 2. 400 g of a 20% strength aqueous hydrochloric acid solution was added to the aqueous solution. It was then cooled to 14 ° C and it took 10 minutes to drip 267 g of butyraldehyde to start the reaction. After reacting at 14 ° C for 40 minutes, the temperature was raised to 65 ° C at a temperature increase rate of about 0.6 ° C / minute, and maintained at 65 ° C for 300 minutes. Then, the reaction solution was cooled to room temperature, and the precipitated granules were separated by filtration, and washed thoroughly with water. The obtained product was poured into a 0.3% sodium hydroxide solution, and heated to 70 ° C for neutralization. Then, the basic compound was removed by washing with water, and the resultant was dried to obtain an ethylene acetal polymer (VAP1). The degree of acetalization of the obtained ethylene acetal polymer was analyzed according to the method described in JIS K6728, and it was 70.2 mol%.

[Examples 2 and 3, and Comparative Examples 1 to 3] Synthesis of VAP2 to VAP6

An ethylene acetal polymer (VAP2 to VAP6) was obtained in the same manner as in Example 1 except that the PVA shown in Table 2 was used instead of the PVA used in Example 1. The pH of the PVA aqueous solution used and the degree of acetalization of each VAP are shown together in Table 2.

<Evaluation of ethylene acetal polymer>

The following physical property values were measured and evaluated for each of the ethylene acetal polymers prepared above.

(Solubility and solution viscosity of ethylene acetal polymer)

The solubility of each of the ethylene acetal polymers was visually observed, and evaluated by visually observing each ethylene acetal polymer in an ethanol/water (95%/5%) solution at 5% by mass. The fully dissolved one was evaluated as "A", and the prepared solution was stirred at 50 ° C for 24 hours, and then the obtained solution was separated by filtration using 5 kinds of C filter paper of JIS P3801, and the ethylene acetal system used for dissolution was used. When the mass ratio of the ethylene acetal polymer remaining on the filter paper in the total amount of the polymer is 0.01% or more and less than 99%, it is evaluated as "B", and the total amount of the ethylene acetal polymer used for dissolution is left in the residual amount. When the mass ratio of the ethylene acetal-based polymer on the filter paper was 99% or more, it was evaluated as "C" when it was almost insoluble. The results are shown in Table 2. Further, when the ethylene acetal polymer was completely dissolved, the obtained solution was allowed to stand in a thermostat at 20 ° C for 2 hours or more, and the solution viscosity (mPa.s) was measured using a Brookfield type viscometer. If the solution viscosity is less than 400 (mPa.s), it can be evaluated that the solution viscosity is depressed. The results are shown together in Table 2.

(adhesion to glass)

It is measured by the method described in International Publication No. 2012/026393. The results are shown together in Table 2.

As shown in Table 2, the ethylene acetal polymers (VAP1 to VAP3) prepared in Examples 1 to 3 were excellent in solubility in an organic solvent such as an alcohol and adhesion to glass, and the viscosity of the obtained solution. The system is depressed.

On the other hand, when the ethylene acetal polymer did not satisfy the predetermined requirements (Comparative Examples 1 to 3), it was hardly dissolved in an organic solvent such as an alcohol (Comparative Example 1 and Comparative Example 2), or even dissolved in When it is dissolved in an organic solvent such as an alcohol, it is also a property which is inferior to glass (Comparative Example 3).

[Industrial availability]

The ethylene acetal polymer of the present invention is excellent in solubility in an alcohol solvent or the like and adhesion to an inorganic substance such as glass, and has a low solution viscosity and excellent handleability. Therefore, the ethylene acetal polymer is suitably used for a laminated film intermediate film composition, a slurry composition for a ceramic capacitor electrode paste, a ceramic green sheet slurry composition, and an ink composition. Various uses such as a coating composition, an adhesive composition, and a thermographic photosensitive material composition.

Claims (8)

An ethylene acetal-based polymer obtained by acetalizing a vinyl alcohol-based polymer, characterized in that the vinyl alcohol-based polymer comprises a monomer unit of the group represented by the formula (1), and satisfying the following formula (I), the degree of acetalization is 45 mol% or more and 80 mol% or less; (In the formula (1), R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ² is a group represented by an alkoxy group, a decyloxy group or OM; and M is a hydrogen atom, an alkali metal or an ammonium group; R ³ and R ⁴ are each independently a hydrogen atom or an alkyl group; the hydrogen atom of the alkyl group, the alkoxy group and the decyloxy group represented by R ¹ to R ⁴ may be replaced by a substituent containing an oxygen atom or a nitrogen atom; m is an integer of 0 to 2; n is an integer of 3 or more; in the case where R ¹ to R ⁴ are respectively present in plural, each of R ¹ to R ^{4 in the} plural exists independently satisfies the above definition); 370 ≦ P × S ≦ 6,000 (I) P: viscosity average degree of polymerization S: content ratio of the monomer unit (% by mole). The ethylene acetal polymer of claim 1, wherein the vinyl alcohol polymer further satisfies the following formulas (II) and (III): 200 ≦ P ≦ 4,000 (II) 0.1 ≦ S ≦ 10 (III) P: viscosity average degree of polymerization S: content ratio of the monomer unit (% by mole). The ethylene acetal polymer of claim 1, wherein n in the formula (1) is an integer of from 6 to 20. The ethylene acetal-based polymer of claim 1, wherein the monomer unit is represented by the following formula (2): (In the formula (2), R ¹ to R ⁴ , m and n have the same meanings as in the formula (1); and X is a direct bond, a divalent hydrocarbon group, or a divalent organic group containing an oxygen atom or a nitrogen atom; R ⁵ Is a hydrogen atom or a methyl group). The ethylene acetal-based polymer of claim 4, wherein X in the formula (2) is as shown in the following formula (3): -CO-NR ⁶ -* (3) (in the formula (3), R ⁶ It is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; * represents a bond to a group represented by the formula (1). The ethylene acetal polymer according to claim 5, wherein R ⁶ in the formula (3) is a hydrogen atom, and n in the formula (2) is an integer of from 3 to 12. The ethylene acetal polymer according to claim 1, wherein the aldehyde used for acetalization is at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, hexanal and benzaldehyde. The ethylene acetal-based polymer of claim 7, wherein the aldehyde used for acetalization is butyraldehyde.