JPH04117408A - Film - Google Patents

Abstract

PURPOSE:To obtain a film which is hydrophilic and is excellent in water and heat resistances by combining vinyl alcohol units with vinyl ester units having a bulky substituent as a side chain in suitable amounts. CONSTITUTION:A polymer comprising structural units of formulas I and II (wherein R<1> is H or hydrocarbyl; R<2> and R<3> are hydrocarbyl, may be combined with each other to form a cyclic hydrocarbyl or may be combined with R<1> to form cyclic hydrocarbyl) and satisfying the relationships: 10<=[I]<90, 10<[II]<=90, and eta<=0.6 (wherein [I], [II] and eta are the content of units I, the content of units II and the block character, respectively) is formed into a film. This film is hydrophilic and is excellent in water and heat resistances, so that it can be desirably used as an agricultural film or sheet, an antistatic film, a packaging film or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to a film made of a polymer composed of vinyl alcohol units and vinyl ester units having bulky substituents in their side chains. The film is hydrophilic and has excellent water resistance and heat resistance, so it can be used as an agricultural film.
Used as sheets, antistatic films, packaging films, etc.

Ran-3 Yama'LWUIL There has been a demand for hydrophilic films, sheets, etc. for a long time, but in recent years there has been a strong demand for antistatic properties, antifogging properties, and moisture permeability. However, these requirements require not only hydrophilic properties but also heat resistance, which is the weak point of hydrophilic materials.
It is often required to have water-based properties and high strength properties at the same time. To date, attempts have been made to impart hydrophilicity by introducing hydrophilic units into a polymer, or by blending hydrophilic polymers or low-molecular compounds; Water resistance tends to decrease as the amount increases), and it is usually extremely difficult to balance sufficient hydrophilicity and water resistance.

The latter method is sometimes effective in improving surface properties, but the effect is not long lasting.

As described above, there is currently a strong demand for films and notebooks that are hydrophilic and have relatively high water absorption and hygroscopicity, while at the same time having excellent (heat) water resistance and strength properties.

Problems to be Solved by C1 Film Under these circumstances, the present invention aims to provide a novel film that is hydrophilic and has excellent (hot) water resistance and strength properties.

D. As a result of intensive studies to solve the above problems, the present inventors have found that a compound having a structural unit represented by the following formula [I] and general formula [I11], and [I] and A film made of a polymer whose content of [II] and block character (η) satisfy the following conditions has excellent transparency, moisture permeability, (hot) water resistance, heat resistance, and high strength properties. Heading: This completes the invention.

[I ko ・ +C) I, -CH+H [I1'J : +CH, -CH)OR' 0= C-C-R' 10≦ [I ko〈90 10< CI[ko≦90 η ≦0.6 ( In the formula, R1 represents a hydrogen atom or a hydrocarbon group, and R2
and R3 each represent a hydrocarbon group, or R1 and R3 together represent a cyclic hydrocarbon group, or R
1, R1 and R3 together represent a cyclic hydrocarbon group. ) The present invention will be explained in more detail below.

The film of the present invention has the above formula [I] and the general formula [I
El] and general formula [n] in which the block character (η) representing the content of [I] and chain distribution of units [I] and [II] in the polymer satisfies the above conditions. Consists of merging.

Examples of hydrocarbon groups that R], R1 and R3 of the general formula [I] may represent individually or together include lower alkyl groups such as methyl, ethyl, propyl and butyl; phenyl groups, etc. Aryl group: 1 to 18 carbon atoms such as cycloalkyl group such as cyclohexyl
Examples include hydrocarbon groups up to. The structure of general formula [I1] is appropriately selected depending on the properties of the intended film, but
For example, trialkyl vinyl acetate such as vinyl pivalate, dimethylethyl vinyl acetate, dimethylethyl vinyl acetate, diethylmethylvinyl acetate, triethyl vinyl acetate, tripropyl vinyl acetate, vinyl versatate, dialkyl vinyl acetate, dimethyl vinyl acetate, diethyl vinyl acetate, etc. Vinyl acetate, methylcyclohexyl vinyl acetate, l
-Vinyl ester units having cycloalkyl such as vinyl norbornanecarboxylate and vinyl 3-noradamantanecarboxylate can be mentioned. Among these, vinyl pivalate and vinyl versatate units are particularly preferred because they are easy to obtain polymers with a high degree of polymerization and are easy to saponify.

The polymer constituting the film of the present invention may include a polymer containing 10 to 90 mol% of units represented by the formula [I] and a polymer containing 90 to 10 mol% of units represented by the general formula [■]. It can be used if it is a combination, but preferably the unit of formula [I] is 2
0 to 90 mol%, [I[] units or 80 to 1O mol%,
More preferably, 30 to 90 mol% of units of formula El],
The unit of [I[] is 70 to 10 mol%. A polymer in which the CIF units are less than 10 mol % and the CIF units are more than 90 mol % will not have sufficient hydrophilicity and will have low strength, making it impossible to achieve the object of the present invention.

Furthermore, the copolymer has structural units of EIE and [■]
The block character (η), which is a characteristic value representing the chain distribution, is 0.6 or less, preferably 0.5 or less, and more preferably 0.4 or less. In a polymer with η exceeding 0.6, even if the contents of formula [G and general formula [■] are within the above range, although hydrophilicity is expressed, sufficient water resistance cannot be obtained and the object of the present invention is still not achieved. unattainable.

Here, the block character -η is expressed by the following formula.

η = [OH, VES]/2[OH ko[Y E S
] (In the formula, [OH, YES] means that among the methylene group carbons measured by C-NMR of the polyvinyl alcohol polymer, the methine carbon substituted with a hydroxyl group and the vinyl ester group represented by the general formula [I] It shows the molar fraction of the substance sandwiched between the substituted methine carbons, and [○H] and rv
Es] is the amount of vinyl alcohol units in the polymer and the amount of vinyl ester units represented by the general formula [N, respectively, expressed as molar fractions. ) η takes a value between ○ and 2 and is ~0 for block polymers.
, 1 for random polymers, and 2 for alternating polymers.As shown by the value of η above, the polymer constituting the film of the present invention has a formula [+] and a general formula [nl]. The structure is similar to that of a so-called multi-block polymer in which the units distributed in blocks are distributed in a fairly block-like manner.

The polymer used in the present invention basically has the general formula [I1]
is obtained by hydrolysis of a homopolymer, particularly a saponification reaction using an alkali catalyst, and within a range that does not impair the effects obtained by the present invention, formula [+] or general formula [
(2) As long as the unit content represented by C is within the above range and the block character -η is 0.6 or less, there are no restrictions on the method or process for producing the polymer, the raw materials used, etc. Furthermore, it is possible to contain units other than formula II or general formula I13 within a range that does not impair the spirit of the present invention, that is, 20 mol % or less, preferably 10 mol % or less, more preferably 5 mol % or less. . Such units include vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl laurate, vinyl stearate, vinyl benzoate, and olefins such as ethylene, propylene, l-butene, and isobutyne. , acrylic acid and its salts and methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate ,
Acrylic acid esters such as dodecyl acrylate and octadecyl acrylate, methacrylic acid and its salts, methyl methacrylate, ethyl methacrylate, n-methacrylate
propyl, i-propyl methacrylate, n methacrylate
-butyl, i-butyl methacrylate, monobutyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, methacrylic acid esters such as octadecyl methacrylate, acrylamide, N-methylacrylamide, N-ethylacrylamide, N.

N-dimethylacrylamide, diacetone acrylamide, acrylamide propane sulfonic acid and its salts,
Acrylamidopropyldimethylamine and its salts and quaternary salts, acrylamide derivatives such as N-methylolacrylamide and its derivatives, methacrylamide, N-
Methyl methacrylamide, N-ethyl methacrylamide, methacrylamide propane sulfonic acid and its salts,
Methacrylamide propyl dimethylamine and its salts and quaternary salts, methacrylamide derivatives such as N-methylolacrylamide and its derivatives, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl Vinyl ethers such as vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, nitriles such as acrylonitrile and methacrylonitrile, vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, allyl acetate, Examples include allyl compounds such as allyl chloride, maleic acid and its salts and esters, itaconic acid and its salts and esters, vinyl silyl compounds such as vinyltrimethoxysilane, and isopropenyl acetate.

However, Dutch patent No. 6509634, R, K, T
S,C,1,MONOGRAPHNo,of ubbs et al.
A copolymer obtained by hydrolyzing only the vinyl acetate units of a copolymer of vinyl acetate and a vinyl ester corresponding to the general formula [■] disclosed in 3088 (1967) is a copolymer obtained by hydrolyzing only the vinyl acetate units of the copolymer disclosed in 3088 (1967).
] and the general formula [I[] are distributed randomly in the polymer, and the block character is close to η~l, and as mentioned above, the film obtained from the copolymer has the following characteristics: The purpose is not achieved.

The molecular weight of the polymer used in the present invention is determined by measuring the polyvinyl ester polymer containing the above-mentioned general formula [I1] at 25°C in acetone before subjecting it to the saponification reaction, and expressing it as an intrinsic viscosity of 0.1 dC. /g or more and 10 dC/g or less. 0. ．． 1df! If it is less than /g, the film strength will not be sufficient, and if it is more than 10d (/g, the moldability will be poor,
(b) Neither of these methods can achieve the purpose of the present invention.

The film of the present invention includes a film or a notebook, and includes an independent film-like molded product usually expressed as a film, a membrane, a sort, etc., a film-like molded product used by laminating with other polymers, etc. It includes.

To form the film or sort of the present invention, a dry film forming method is used in which a polymer solution prepared using a single or mixed solvent selected depending on the composition of the polymer is cast or extruded, and then the solvent is removed by evaporation. , a wet film forming method in which a polymer solution is extruded into a solvent that does not dissolve the polymer, coagulates and forms a film, and a polymer solution that dissolves at high temperatures but becomes a solution or gel at low temperatures is prepared; A gel film forming method in which the polymer is solidified by gelation and then extracted and removed to form a film can be used, and it is also possible to mold the polymer from a molten state depending on the composition and degree of polymerization, and the present invention utilizes these molding methods. When using a solvent in these molding steps, it may be used without any particular restrictions as long as it dissolves the polymer, and among these, dimethyl sulfate, dimethyl formamide, dimethyl acetamide, Water, ethylene glycol methyl ether, ethylene glycol methyl ether, tetrahydrofuran, methyl ethyl ketone, methylene chloride, dichloroethane, chlorobenzene, nochlorohenzene, etc. are used alone or in combination.The temperature during molding varies depending on the molding method, but
It is between -20°C and 300°C.

In addition to the above-mentioned polymers, the film of the present invention may contain plasticizers, anti-aging agents, ultraviolet absorbers, etc. as necessary, and may also contain other types of polymers as long as they do not impair the effects of the present invention. There are no restrictions, and examples of plasticizers include dibutyl phthalate, dioctyl phthalate, tricrylene phosphate,
triethylene glycol-di-2-ethylbutyrate,
Glycerin, ethylene glycol, diethylene glycol, triethylene glycol, etc. are used. Furthermore, organic and inorganic pigments, dyes, various inorganic powders, and the like may be added as necessary.

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited in any way by the examples.

Note that "parts" in the examples represent "parts by weight" unless otherwise specified.

E, LLL Examples 1 to 3 In a reaction vessel equipped with a stirrer, vinyl pivalate monomer 1 was added.
000 parts of methanol and 1001 parts of methanol were charged, and the system was purged with nitrogen by nitrogen gas bubbling. Separately, 0.50 2,2-azobisisobutyronitrile is added to methanol as an initiator.
A solution was prepared by dissolving 1 part, and the atmosphere was replaced with nitrogen by bubbling with nitrogen gas. The temperature of the reaction vessel was raised, and when the internal temperature reached 60°C, a methanol solution in which an initiator was dissolved was injected to initiate polymerization.

After 200 minutes, when the polymerization rate reached 70%, the polymerization was stopped by cooling, and unreacted vinyl pivalate/7- was removed under reduced pressure while occasionally adding t-butanol. It was made into a butanol solution. Subsequently, t-butanol was removed under reduced pressure, and then tetrahydrofuran (THF) was added to obtain a 15.0 tvt% THF solution of vinyl polypivalate.

Next, three reactors equipped with a stirrer and a reflux condenser were prepared, and 66.7 parts of the polymer solution was weighed into each reactor.
After heating the mixture to 60° C. and purging with nitrogen gas and maintaining the temperature at 60° C., 21 parts of a 25% methanol solution of potassium hydroxide prepared separately and purged with nitrogen was added and thoroughly stirred.

After being held at 60°C for different predetermined times, acetic acid 6.
8 parts were added along with 20 parts of methanol to neutralize the potassium hydroxide. Subsequently, the gelled material was crushed and washed with Soxhlet methanol, and the ungelled material was precipitated in a mixed solvent of methanol/water (weight ratio 80/20) to recover the polyvinyl alcohol-based polymer, and then washed with acetone-methanol. The reprecipitation operation was performed twice in a water system to purify each product.

The obtained polyvinyl alcohol was measured by d, -DMSO+=solution ML, and 'H-NMR to determine the amount of vinyl alcohol units and the amount of vinyl pivalate units. Also d, -DMS
The block character -η was determined from the C-NMR measurement of the solution of O. The results are summarized in Table 1.

In order to evaluate the degree of polymerization of vinyl polypivalate before being subjected to the saponification reaction, [η] was measured at 25°C in acetone and found to be 0.44 df2/g.

Examples 4-6 Polyvinyl alcohol system 1 obtained in Examples 1-3! Transparency, saturated water absorption rate (30°C), and change in shape after immersing the film in water at 120'C for 30 minutes were examined for the sample made into a film by heat pressing (250°C, 210 minutes). The results are shown in Table 2.

As described above, the film obtained by the present invention has excellent transparency,
It is clear that the film has an appropriate water absorption rate and excellent hot water resistance.

According to the present invention, a film that is hydrophilic, water resistant, heat resistant, and hot water resistant can be obtained. Films with such properties contain a moderate amount of hydrophilic vinyl alcohol units and hydrophobic vinyl ester units with bulky substituents, and have a so-called multi-block structure in which the distribution is block-like. This was obtained for the first time by using a polymer.

The film obtained by the present invention can be used in fields that take advantage of the above characteristics, such as agricultural films, antistatic films, packaging films, interlayer films for safety glass, gas separation films, antithrombotic films, and moisture permeable films. It is useful as

Patent applicant RiRashi Co., Ltd.

Claims (1)

[Claims] (1) A polymer that has a structural unit represented by the following formula [I] and general formula [II], and whose contents of [I] and [II] and block character (η) satisfy the following conditions: More film. [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II]:▲There are mathematical formulas, chemical formulas, tables, etc.▼ 10≦[I]<90 10<[II]≦90 η≦0.6 (in the formula , R^1 represents a hydrogen atom or a hydrocarbon group, and R
^2 and R^3 each represent a hydrocarbon group, or R^2 and R^3 represent a cyclic hydrocarbon group formed together; R^1, R^2 and R^3 represents a cyclic hydrocarbon group formed together. )