JP5041693B2 - Raw film for laminating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide original film for laminating use comprising an ethylene-vinyl alcohol copolymer composition and excellent in adhesion and surface smoothness. <P>SOLUTION: The original film for laminating use is made from an ethylene-vinyl alcohol copolymer containing structural units of the formula(1)( wherein, X is any linkage chain except ether linkage; R1 to R4 are each any substituent; and n is 0 or 1 ). <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an original film for laminating using a novel ethylene-vinyl alcohol copolymer, and more particularly to an original film for laminating excellent in surface smoothness and adhesiveness.

  In general, an ethylene-vinyl alcohol copolymer (hereinafter abbreviated as EVOH) is excellent in transparency, gas barrier properties, fragrance retention, solvent resistance, oil resistance, and the like. Used in various packaging materials such as materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, etc., but the gas barrier property of such EVOH is affected by humidity and tends to be hard and brittle as a mechanical feature. In order to improve these properties, a stretching treatment is performed.

However, EVOH is inferior in stretchability compared to other resins, so that it is difficult to stretch, and the stretched film cannot have a sufficient stretch effect for gas barrier properties, as well as reduced in appearance. was there. Thus, a method has been proposed in which EVOH is stretched under special conditions to obtain an EVOH film having good appearance and barrier properties (see, for example, Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 50-144776 Japanese Patent Laid-Open No. 10-180867

  However, EVOH is rarely used as a single-layer film, and a film formed or a film stretched after film formation is often used by being bonded to another resin film. When bonding with other resin films, if you use a cheap adhesive widely used, or if you increase the bonding speed to increase production efficiency, the adhesive strength tends to decrease, There is an insufficient study on such a decrease in adhesive strength, and there is a need for an EVOH film that can be stretched smoothly and that provides high adhesive strength when the obtained film is bonded to another resin film. Yes. Also, printing may be performed on the EVOH layer surface before bonding, and if there is roughness on the EVOH layer surface at that time, an unprinted part called printing skip may be formed, and the film surface smoothness may be is needed.

（ ここで、Ｘ は炭素数６ 以下のアルキレン基で、Ｒ １ 〜 Ｒ ４ は水素原子であり、ｎ は０ または１ を表す。）
本発明においては、上記の構造単位（ １ ）を０ ． １ 〜 ３ ０ モル％ 含有すること、ホウ素化合物がホウ素換算でＥ Ｖ Ｏ Ｈ １ ０ ０ 部に対して０ ． ０ ０ １ 〜 １ 重量部含有する等のＥ Ｖ Ｏ Ｈ を用いることが好ましい実施態様である。

Accordingly, as a result of intensive studies in view of the present situation, the present inventor used E V O H containing the following structural unit (1) and having an ethylene content of 20 to 60 mol% . The present invention was completed by finding that the film for laminate raw material meets the above-mentioned purpose.

(Here, X is an alkylene group having 6 or less carbon atoms, R 1 to R 4 are hydrogen atoms, and n represents 0 or 1.)
In the present invention, the structural units of (1) above 0. 1 to 30 mol%, and the boron compound is 0. 0 with respect to 100 parts of EVOH in terms of boron. It is a preferred embodiment to use EVOH such as containing 0 0 1 to 1 part by weight.

  Since the laminate film for use in the present invention uses EVOH having a specific structural unit, it is excellent in stretchability, and a film having high surface smoothness and high adhesiveness can be obtained with respect to the stretched film. is there.

Hereinafter, the present invention will be specifically described.
EVOH used for the film for laminate raw material of the present invention contains the structural unit (1), that is, the structural unit having a 1,2-glycol bond in the side chain. in H, and its molecular chains 1, 2 - for the binding chain connecting the glycol bond structure (X), the alkylene carbon number of 6 or less. Further, from the viewpoint of good gas barrier performance of E V O H, those having a smaller number of carbon atoms are preferable, and a structure in which a 1,2-glycol bond structure in which n = 0 is directly bonded to a molecular chain is the most. preferable. Further, preferred in view of water MotoHara child is easily available monomers regard R 1 ~ R 4, further preferred in that a hydrogen atom is excellent gas barrier properties of E V O H.

  The method for producing EVOH is not particularly limited, but when a structural unit in which a 1,2-glycol bond structure is directly bonded to the main chain which is the most preferable structure is taken as an example, 3,4-diol-1-butene, vinyl A method of saponifying a copolymer obtained by copolymerizing an ester monomer and ethylene, a copolymer obtained by copolymerizing 3,4-diasiloxy-1-butene, a vinyl ester monomer and ethylene Saponification method, 3-acyloxy-4-ol-1-butene, vinyl ester monomer and copolymer obtained by copolymerizing ethylene, 4-acyloxy-3-ol-1- A method for saponifying a copolymer obtained by copolymerizing butene, a vinyl ester monomer and ethylene, 3,4-diacyloxy-2-methyl-1-butene Saponifying a copolymer obtained by copolymerizing a vinyl ester monomer and ethylene, copolymerizing 2,2-dialkyl-4-vinyl-1,3-dioxolane, vinyl ester monomer and ethylene And a method of saponifying and decarboxylating a copolymer obtained by copolymerizing vinyl ethylene carbonate, a vinyl ester monomer and ethylene. Moreover, as what has alkylene as a coupling chain (X), 4,5-diol- 1-pentene, 4, 5- diacyloxy-1-pentene, 4, 5-diol-3-methyl- 1-pentene, 4, Copolymers obtained by copolymerizing 5-diol-3-methyl-1-pentene, 5,6-diol-1-hexene, 5,6-diacyloxy-1-hexene and the like with vinyl ester monomers and ethylene The method of saponifying a copolymer obtained by copolymerizing 3,4-diasiloxy-1-butene, a vinyl ester monomer and ethylene is excellent in copolymerization reactivity. It is preferable to use 3,4-diacetoxy-1-butene as 3,4-diacyloxy-1-butene. A mixture of these monomers may also be used. Further, 3,4-diacetoxy-1-butane, 1,4-diacetoxy-1-butene, 1,4-diacetoxy-1-butane and the like may be contained as a small amount of impurities. Moreover, although such a copolymerization method is demonstrated below, it is not limited to this.

（ここで、Ｒはアルキル基であり、好ましくはメチル基である。）

（ここで、Ｒはアルキル基であり、好ましくはメチル基である。）

（ここで、Ｒはアルキル基であり、好ましくはメチル基である。）
なお、上記の（２）式で示される化合物は、イーストマンケミカル社から、上記（３）式で示される化合物はイーストマンケミカル社やアクロス社から入手することができる。 The 3,4-diol-1-butene is represented by the following formula (2), and the 3,4-diacyloxy-1-butene is represented by the following formula (3), 3-acyloxy-4-ol-1-butene. Represents the following formula (4), and 4-acyloxy-3-ol-1-butene is represented by the following formula (5).

(Here, R is an alkyl group, preferably a methyl group.)

(Here, R is an alkyl group, preferably a methyl group.)

(Here, R is an alkyl group, preferably a methyl group.)
The compound represented by the above formula (2) can be obtained from Eastman Chemical Co., and the compound represented by the above formula (3) can be obtained from Eastman Chemical Co. or Acros.

  Examples of vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, Although vinyl versatate etc. are mentioned, vinyl acetate is preferably used especially from an economical viewpoint.

  There are no particular limitations on the copolymerization of 3,4-diacyloxy-1-butene, vinyl ester monomer, and ethylene, and known methods such as bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization, or emulsion polymerization may be used. Although it can be employed, solution polymerization is usually performed.

The method for charging the monomer component at the time of copolymerization is not particularly limited, and any method such as batch charging, split charging, continuous charging, etc. may be employed.
In addition, as a method for introducing ethylene into the copolymer, ordinary ethylene pressure polymerization may be carried out, and the amount introduced can be controlled by the pressure of ethylene, and can be controlled according to the intended ethylene content. However, it is usually selected from the range of 25 to 80 kg / cm ² .

Examples of the solvent used in such copolymerization include usually lower alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone and methyl ethyl ketone, and industrially, methanol is preferably used.
The amount of the solvent used may be appropriately selected in consideration of the chain transfer constant of the solvent in accordance with the degree of polymerization of the target copolymer. For example, when the solvent is methanol, S (solvent) / M ( Monomer) = 0.01 to 10 (weight ratio), preferably 0.05 to 7 (weight ratio).

In the copolymerization, a polymerization catalyst is used. Examples of the polymerization catalyst include known radical polymerization catalysts such as azobisisobutyronitrile, acetyl peroxide, benzoyl peroxide, lauryl peroxide, and t-butylperoxyneodeca Noate, t-butylperoxypivalate, α, α′bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3, -tetramethylbutylperoxyneodeca Peroxyesters such as noate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-hexylperoxypivalate, di-n-propylperoxydi Carbonate, di-iso-propyl peroxydicarbonate], di-sec- Til peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, dimethoxybutyl peroxydicarbonate, di Peroxydicarbonates such as (3-methyl-3-methoxybutylperoxy) dicarbonate, diacyl peroxides such as 3,3,5-trimethylhexanoyl peroxide, diisobutyryl peroxide, lauroyl peroxide, etc. Examples include low temperature active radical polymerization catalysts, and the amount of polymerization catalyst used varies depending on the type of catalyst and cannot be determined unconditionally, but is arbitrarily selected according to the polymerization rate. For example, when azobisisobutyronitrile or acetyl peroxide is used, 10 to 2000 ppm is preferable with respect to the vinyl ester monomer, and 50 to 1000 ppm is particularly preferable.
Moreover, it is preferable to select the reaction temperature of a copolymerization reaction from the range of about 40 degreeC-a boiling point by the solvent and pressure to be used.

  In the present invention, it is also preferred that a hydroxylactone compound or hydroxycarboxylic acid coexist with the catalyst, and the hydroxylactone compound is not particularly limited as long as it has a lactone ring and a hydroxyl group in the molecule. L-ascorbic acid, erythorbic acid, glucono delta lactone and the like can be mentioned. L-ascorbic acid and erythorbic acid are preferably used, and hydroxycarboxylic acids include glycolic acid, lactic acid, glyceric acid, apple Acid, tartaric acid, citric acid, salicylic acid and the like can be mentioned, and citric acid is preferably used.

  The hydroxylactone compound or hydroxycarboxylic acid is used in an amount of 0.0001 to 0.1 parts by weight (further 0.0005 to 0.005 parts per 100 parts by weight of vinyl acetate) in both batch and continuous systems. 05 parts by weight, particularly 0.001 to 0.03 parts by weight), and if the amount used is less than 0.0001 parts by weight, the coexistence effect may not be sufficiently obtained. Exceeding this is undesirable because it results in inhibition of the polymerization of vinyl acetate. There is no particular limitation on charging such a compound into the polymerization system, but it is usually charged into a polymerization reaction system by diluting with a solvent such as an aliphatic ester containing lower aliphatic alcohol or vinyl acetate, water, or a mixed solvent thereof. .

  The copolymerization ratio of 3,4-diasiloxy-1-butene and the like is not particularly limited, but the copolymerization ratio may be determined in accordance with the amount of the structural unit (1) introduced.

  In the present invention, an ethylenically unsaturated monomer that can be copolymerized may be copolymerized as long as the effects of the present invention are not impaired during the above copolymerization. Examples of such monomers include propylene, 1 -Olefins such as butene and isobutene, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid and (anhydrous) itaconic acid, or salts thereof, or those having 1 to 18 carbon atoms Mono- or dialkyl esters, acrylamide, N-alkyl acrylamide having 1 to 18 carbon atoms, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or its salt, acrylamidopropyldimethylamine or its acid salt or its quaternary salt, etc. Acrylamides, methacrylamide, N-alkyl methacryl having 1 to 18 carbon atoms Methacrylamides such as amide, N, N-dimethylmethacrylamide, 2-methacrylamide propanesulfonic acid or salts thereof, methacrylamide propyldimethylamine or acid salts thereof or quaternary salts thereof, N-vinylpyrrolidone, N-vinylformamide N-vinylamides such as N-vinylacetamide, vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ethers, alkoxyalkyl vinyl ethers, vinyl chloride, vinylidene chloride , Vinyl halides such as vinyl fluoride, vinylidene fluoride, vinyl bromide, vinyl silanes, allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, trimethyl- (3- Acrylamide-3-dimethylpropyl) - ammonium chloride, acrylamido-2-methylpropanesulfonic acid, glycerol monoallyl ether, ethylene carbonate, and the like.

  Furthermore, N-acrylamidomethyltrimethylammonium chloride, N-acrylamidoethyltrimethylammonium chloride, N-acrylamidopropyltrimethylammonium chloride, 2-acryloxyethyltrimethylammonium chloride, 2-methacryloxyethyltrimethylammonium chloride, 2-hydroxy-3- Cationic group-containing monomers such as methacryloyloxypropyltrimethylammonium chloride, allyltrimethylammonium chloride, methallyltrimethylammonium chloride, 3-butenetrimethylammonium chloride, dimethyldiallylammonium chloride, diethyldiallylammonium chloride, acetoacetyl group-containing monomers And so on.

  Further, vinyl silanes include vinyl trimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, vinylisobutyldimethoxysilane, vinylethyldimethoxysilane, vinylmethoxydioxysilane. Butoxysilane, vinyldimethoxybutoxysilane, vinyltributoxysilane, vinylmethoxydihexyloxysilane, vinyldimethoxyhexyloxysilane, vinyltrihexyloxysilane, vinylmethoxydioctyloxysilane, vinyldimethoxyoctyloxysilane, vinyltrioctyloxysilane , Vinylmethoxydilauryloxysilane, vinyldimethoxylauryloxysilane, vinylmethoxydioleoxysilane And vinyl dimethoxy I acetoxyphenyl silane.

  The obtained copolymer is then saponified. In such saponification, an alkali catalyst or an acid catalyst is used in a state where the copolymer obtained above is dissolved in alcohol or hydrous alcohol. Done. Examples of the alcohol include methanol, ethanol, propanol, tert-butanol and the like, and methanol is particularly preferably used. The concentration of the copolymer in the alcohol is appropriately selected depending on the viscosity of the system, but is usually selected from the range of 10 to 60% by weight. Catalysts used for saponification include alkali catalysts such as alkali metal hydroxides and alcoholates such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium methylate, lithium methylate, etc., sulfuric acid, Examples include acid catalysts such as hydrochloric acid, nitric acid, metasulfonic acid, zeolite, and cation exchange resin.

The amount of the saponification catalyst used is appropriately selected depending on the saponification method, the target degree of saponification, and the like. Usually, when an alkali catalyst is used, a vinyl ester monomer and 3,4-diacyloxy-1- 0.001-0.1 equivalent with respect to the total amount of butenes, Preferably 0.005-0.05 equivalent is suitable.
The pressure during saponification cannot be generally specified depending on the target ethylene content, but is selected from the range of ^{2 to} 7 kg / cm ² , and the temperature at this time is 80 to 150 ° C., preferably from 100 to 130 ° C. Selected.

  Thus, EVOH used in the present invention can be obtained. In the present invention, the ethylene content and saponification degree of the obtained EVOH are not particularly limited, but are 10 to 60 mol% (more preferably 20 to 20%). 50 mol%, particularly 25 to 48 mol%) and a saponification degree of 90 mol% or more (more preferably 95 mol% or more, particularly 99 mol% or more) are preferably used. If it is less than mol%, the gas barrier property and appearance at high humidity tend to be lowered. Conversely, if it exceeds 60 mol%, the gas barrier property tends to be lowered. Further, if the saponification degree is less than 90 mol%, the gas barrier property and It is not preferable because moisture resistance and the like tend to decrease.

Further, the amount of the structural unit (structural unit having a 1,2-glycol bond) introduced into the obtained EVOH is not particularly limited, but is 0.1 to 30 mol% (more preferably 0.5 to 20 mol%, particularly 1 to 10 mol%) is preferable. If the amount introduced is less than 0.1 mol%, the effect of the present invention is not sufficiently exhibited, and conversely if it exceeds 30 mol%, the gas barrier property is lowered. It tends to be unfavorable. Further, in adjusting the amount of structural units having 1,2-glycol bonds, it is also possible to adjust by blending at least two types of EVOH having different introduction amounts of structural units having 1,2-glycol bonds. At least one of them may not have a structural unit having a 1,2-glycol bond.
With regard to EVOH in which the 1,2-glycol bond amount is adjusted in this way, the 1,2-glycol bond amount can be calculated by weight average, and the ethylene content can also be calculated by weight average. However, precisely, the ethylene content and the 1,2-glycol bond amount can be calculated from the measurement result of ¹ H-NMR described later.

EVOH having the structural unit (1) obtained by such a method can be used as it is, but further, acids such as acetic acid and phosphoric acid, and alkali metals and alkaline earths thereof, as long as the object of the present invention is not impaired. Addition of metal salts such as metals and transition metals, or boric acid or a metal salt thereof as a boron compound is preferable in terms of improving the thermal stability of the resin.
The amount of acetic acid added is preferably 0.001 to 1 part by weight (more preferably 0.005 to 0.2 part by weight, particularly 0.010 to 0.1 part by weight) with respect to 100 parts by weight of EVOH. If the addition amount is less than 0.001 part by weight, the content effect may not be sufficiently obtained. Conversely, if the addition amount exceeds 1 part by weight, the appearance of the resulting molded product tends to deteriorate, which is not preferable.

  Metal borate salts include calcium borate, cobalt borate, zinc borate (zinc tetraborate, zinc metaborate, etc.), aluminum borate / potassium borate, ammonium borate (ammonium metaborate, ammonium tetraborate, pentaborate) Ammonium phosphate, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate, cadmium tetraborate, etc.), potassium borate (potassium metaborate, potassium tetraborate, potassium pentaborate, potassium hexaborate, octaborate) Potassium), silver borate (silver metaborate, silver tetraborate, etc.), copper borate (cupric borate, copper metaborate, copper tetraborate, etc.), sodium borate (sodium metaborate, two Sodium borate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.), boric acid (Lead metaborate, lead hexaborate, etc.), nickel borate (nickel orthoborate, nickel diborate, nickel tetraborate, nickel octaborate, etc.), barium borate (barium orthoborate, barium metaborate, two Barium borate, barium tetraborate, etc.), bismuth borate, magnesium borate (magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate, etc.), manganese borate ( (Manganese borate, manganese metaborate, manganese tetraborate, etc.), lithium borate (lithium metaborate, lithium tetraborate, lithium pentaborate, etc.), borax, carnite, inioite, and goethite , Borate minerals such as suian stone, zaiberite and the like, preferably borax, C acid, sodium borate (sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate acid, eight sodium borate, etc.). Moreover, as an addition amount of a boron compound, 0.001-1 weight part (further 0.002-0.2 weight part, especially 0.005-0 in conversion of boron with respect to 100 weight part of all EVOH in a composition). .1 part by weight), and if the amount added is less than 0.001 part by weight, the effect of the content may not be sufficiently obtained. It is not preferable because it tends to deteriorate.

  Such metal salts include sodium, potassium, calcium, magnesium, and other organic acids such as acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, oleic acid, and behenic acid, sulfuric acid, sulfurous acid, carbonic acid, and phosphoric acid. And metal salts of inorganic acids such as acetate, phosphate and hydrogen phosphate are preferred. The amount of the metal salt added is 0.0005 to 0.1 parts by weight (more 0.001 to 0.05 parts by weight, particularly 0.002 to 0.005 parts by weight) with respect to 100 parts by weight of EVOH. 03 parts by weight), and if the amount added is less than 0.0005 parts by weight, the effect of the content may not be sufficiently obtained. Tends to deteriorate. In addition, when adding 2 or more types of alkali metal and / or alkaline-earth metal salt to EVOH, it is preferable that the total is in the range of said addition amount.

  The method of adding acids or metal salts thereof to EVOH is not particularly limited. A) A porous precipitate of EVOH having a water content of 20 to 80% by weight is contacted with an aqueous solution of acids or metal salts thereof to form acids. And a method of drying after containing a metal salt thereof, and a) adding an acid or a metal salt thereof into a uniform EVOH solution (water / alcohol solution, etc.), and then extruding it into a coagulating solution in a strand form. A method of further cutting the strands into pellets, further drying treatment, c) a method in which EVOH and acids and their metal salts are mixed together, and then melt-kneading with an extruder, etc., and d) during the production of EVOH, The alkali (sodium hydroxide, potassium hydroxide, etc.) used in the saponification process is neutralized with acids such as acetic acid, and residual acids such as acetic acid and by-products such as sodium acetate and potassium acetate are obtained. And a method like or to adjust the water washing treatment the amount of Li metal salt. In order to obtain the effects of the present invention more remarkably, the methods a), b) and d), which are excellent in dispersibility of acids and metal salts thereof, are preferred.

The EVOH composition obtained by the above methods a), b) or d) is dried after salts and metal salts are added.
As such a drying method, various drying methods can be employed. For example, fluidized drying in which substantially pellet-like EVOH is stirred and dispersed mechanically or with hot air, or substantially pellet-like EVOH is not subjected to dynamic actions such as stirring and dispersion. Examples of dryers for fluidized drying include cylindrical / groove-type stirred dryers, circular tube dryers, rotary dryers, fluidized bed dryers, vibrating fluidized bed dryers, and conical rotations. In addition, as a dryer for performing stationary drying, a batch type box dryer is used as a stationary material type, a band dryer, a tunnel dryer, and a vertical dryer are used as a material transfer type. Although a vessel etc. can be mentioned, it is not limited to these. It is also possible to combine fluidized drying and stationary drying.

  Air or an inert gas (nitrogen gas, helium gas, argon gas, etc.) is used as the heating gas used in the drying process, and the temperature of the heating gas is 40 to 150 ° C., which is the productivity and the heat of EVOH. It is preferable in terms of preventing deterioration. The time for the drying treatment is usually from about 15 minutes to 72 hours, although it depends on the water content of EVOH and the amount of treatment, from the viewpoint of productivity and prevention of thermal degradation of EVOH.

  The EVOH composition is subjected to a drying treatment under the above-mentioned conditions. The water content of the EVOH composition after the drying treatment is 0.001 to 5% by weight (more preferably 0.01 to 2% by weight, particularly preferably 0.00%). 1 to 1 part by weight), and if the water content is less than 0.001% by weight, the long run moldability tends to decrease. There is a possibility that foaming may occur, which is not preferable.

  Thus, the target EVOH or a composition thereof (hereinafter collectively referred to as an EVOH composition) can be obtained. However, in such an EVOH composition, some monomer residue is contained within a range that does not impair the object of the present invention. (3,4-diol-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-ol-1-butene, 4-acyloxy-3-ol-1-butene, 4,5-diol -1-pentene, 4,5-diacyloxy-1-pentene, 4,5-diol-3-methyl-1-pentene, 4,5-diol-3-methyl-1-pentene, 5,6-diol-1 -Hexene, 5,6-diacyloxy-1-hexene, 4,5-diacyloxy-2-methyl-1-butene, etc.) and saponified monomers (3,4-diol-1-butene, 4,5- All-1-pentene, 4,5-diol-3-methyl-1-pentene, 4,5-diol-3-methyl-1-pentene, 5,6-diol-1-hexene, etc.) Good.

In addition, the EVOH used in the present invention is preferably a blend of EVOH containing the structural unit (1) and another EVOH different from this from the viewpoint of improving the gas barrier property and pressure resistance. Examples of EVOH include those having different structural units, those having different ethylene contents, those having different degrees of saponification, and those having different molecular weights.
Examples of the EVOH having a structural unit different from the EVOH having the structural unit (1) include, for example, an EVOH composed only of an ethylene structural unit and a vinyl alcohol structural unit, and a modified EVOH having a functional group such as a 2-hydroxyethoxy group in the side chain of the EVOH. Can be mentioned.
Moreover, when using what has different ethylene content, the structural unit may be the same or different, but the ethylene content difference is 1 mol% or more (further 2 mol% or more, particularly 2 to 2 mol%). 20 mol%). If the ethylene content difference is too large, the transparency may be deteriorated, which is not preferable. Moreover, the manufacturing method of 2 or more types of different EVOH (blend product) is not particularly limited, for example, a method of mixing each paste of EVA before saponification and then saponifying, alcohol of each EVOH after saponification or water and alcohol And a method of mixing each solution of EVOH in the form of pellets or powder, and then melt-kneading.

  The melt flow rate (MFR) (210 ° C., load 2160 g) of the EVOH composition thus obtained is not particularly limited, but is 0.1 to 100 g / 10 minutes (more preferably 0.5 to 50 g / 10 minutes, particularly 1 to 30 g / 10 min.) When the melt flow rate is smaller than the above range, the extruder tends to be in a high torque state during molding, making extrusion difficult. Is too large, the appearance and gas barrier properties tend to decrease, which is not preferable.

  In addition, EVOH used in the present invention includes saturated aliphatic amides (such as stearic acid amide), unsaturated fatty acid amides (such as oleic acid amide), bis fatty acid amides (such as oleic acid amide) within the range not impairing the object of the present invention. For example, lubricants such as ethylene bis-stearic acid amide), fatty acid metal salts (e.g., calcium stearate, magnesium stearate, etc.), low molecular weight polyolefin (e.g., low molecular weight polyethylene having a molecular weight of about 500 to 10,000, or low molecular weight polypropylene), Inorganic salts (for example, hydrotalcite), plasticizers (for example, aliphatic polyhydric alcohols such as ethylene glycol, glycerin, hexanediol), oxygen absorbers (for example, reduced iron powders as inorganic oxygen absorbers, To which water-absorbing substances and electrolytes are added, aluminum powder, Potassium sulfate, photocatalytic titanium oxide, etc. as organic compound-based oxygen absorbers, ascorbic acid, fatty acid esters and metal salts thereof, hydroquinone, gallic acid, polyhydric phenols such as hydroxyl group-containing phenol aldehyde resin, bis-salicyl aldehyde -Coordination conjugate of nitrogen-containing compound and transition metal such as imine cobalt, tetraethylenepentamine cobalt, cobalt-Schiff base complex, porphyrins, macrocyclic polyamine complex, polyethyleneimine-cobalt complex, terpene compound, amino acids Reactive substances of hydroxyl group-containing reducing substances, triphenylmethyl compounds, etc. are used as polymer oxygen absorbers as coordination bonds of nitrogen-containing resins and transition metals (example: combination of MXD nylon and cobalt), tertiary Blends of hydrogen-containing resins and transition metals (eg polyp (A combination of propylene and cobalt), a blend of a carbon-carbon unsaturated bond-containing resin and a transition metal (eg, a combination of polybutadiene and cobalt), a photooxidative decay resin (eg, polyketone), an anthraquinone polymer (eg, polyvinyl) Anthraquinone), etc., and further, photoinitiators (benzophenone, etc.), peroxide supplements (commercial antioxidants, etc.) and deodorants (activated carbon, etc.) added to these blends), heat stabilizers, etc. , Light stabilizers, antioxidants, ultraviolet absorbers, colorants, antistatic agents, surfactants, antibacterial agents, antiblocking agents, slip agents, fillers (eg inorganic fillers), other resins (eg polyolefins, polyamides) Etc.) and the like.

  Such an EVOH composition is formed into a film mainly by melt molding. The melt molding method will be described below. The conditions at the time of melt molding are not particularly limited, but are usually formed by extrusion using a non-vented, screw-type extruder at a melting temperature of 190 to 250 ° C. Usually, a screw having a compression ratio of 2.0 to 4.5 is used to form a film using a T die or a round die.

  The thickness of the EVOH film cannot be generally specified depending on the application, container form, required physical properties, and the like, but is usually selected from a range of about 2 to 500 μm (more preferably 3 to 200 μm).

  Stretching the EVOH film thus obtained is also important for improving the physical properties of the film. When stretching, either uniaxial stretching or biaxial stretching may be performed, and it is better in terms of physical properties to perform stretching as high as possible. In the case of uniaxial stretching, the physical properties are preferably 5 times or more, particularly 10 times or more, and in the case of biaxial stretching, the area magnification is 5 times or more, particularly 10 times or more.

  As the stretching method, a roll stretching method, a tenter stretching method, a tubular stretching method, a stretching blow method, or the like can be employed. In the case of biaxial stretching, both a simultaneous biaxial stretching method and a sequential biaxial stretching method can be employed. The stretching temperature is selected from the range of about 70 to 160 ° C, preferably about 80 to 150 ° C.

  Thus, after stretching is completed, heat setting is then performed. The heat setting can be carried out by a known means, and the heat treatment is performed at 80 to 170 ° C., preferably 100 to 160 ° C. for about 2 to 600 seconds while keeping the stretched film in a tension state.

  The EVOH laminate raw film obtained in the present invention is further bonded to another base resin film. In the production thereof, on one side or both sides of the resin molded product layer of the film of the present invention. Another substrate is laminated. Examples of the laminating method include a method of laminating the resin molded product and the film or sheet of another base material using a known adhesive such as an organic titanium compound, an isocyanate compound, or a polyester compound. Also, the EVOH layer may be printed before such a laminating operation. As such other substrates, the same thermoplastic resins as described above are useful.

  The multilayer film thus obtained is subjected to cooling treatment, rolling treatment, printing treatment, dry laminating treatment, solution or melt coating treatment, bag making processing, deep drawing processing, box processing, tube processing, split processing, etc. as necessary. The

  The multilayer film thus obtained has good gas barrier properties, good adhesion and can be obtained without printing defects, and can be used as various packaging materials such as foods, pharmaceuticals, industrial chemicals and agricultural chemicals. Useful.

  Hereinafter, the method of the present invention will be specifically described with reference to examples. In the following, “%” means a weight basis unless otherwise specified.

Polymerization example 1
An EVOH composition (A1) was obtained by the following method.
A 1 m ³ polymerization can with a cooling coil is charged with 500 kg of vinyl acetate, 35 kg of methanol, 500 ppm of acetyl peroxide (vs. vinyl acetate), 20 ppm of citric acid, and 14 kg of 3,4-diacetoxy-1-butene, and the system is nitrogen After substituting once with gas, then substituting with ethylene, injecting until the ethylene pressure reaches 45 kg / cm ² , stirring, and then raising the temperature to 67 ° C., and 3,4-diacetoxy-1-butene Polymerization was carried out while adding a total amount of 4.5 kg at 15 g / min, and polymerization was carried out for 6 hours until the polymerization rate reached 50%. Thereafter, the polymerization reaction was stopped to obtain an ethylene-vinyl acetate copolymer having an ethylene content of 38 mol%.
A methanol solution of the ethylene-vinyl acetate copolymer was supplied at a rate of 10 kg / hour from the top of the plate tower (saponification tower), and at the same time 0.012% of the remaining acetic acid groups in the copolymer. A methanol solution containing an equivalent amount of sodium hydroxide was fed from the top of the tower. On the other hand, methanol was supplied at 15 kg / hour from the bottom of the tower. The tower temperature was 100 to 110 ° C., and the tower pressure was 3 kg / cm ² G. From 30 minutes after the start of charging, a methanol solution of EVOH having a structural unit having a 1,2-glycol bond (EVOH 30%, methanol 70%) was taken out. The saponification degree of the vinyl acetate component of EVOH was 99.5 mol%.

  Next, the obtained methanol solution of EVOH was supplied at 10 kg / hour from the top of the methanol / water solution adjusting tower, methanol vapor at 120 ° C. was supplied at 4 kg / hour, and water vapor was supplied from the bottom of the tower at a rate of 2.5 kg / hour. At the same time, methanol was distilled from the top of the column at 8 kg / hour, and at the same time, 6 equivalents of methyl acetate with respect to the amount of sodium hydroxide used in the saponification was charged from the middle of the column at 95-110 ° C. From this, a water / alcohol solution of EVOH (resin concentration: 35%) was obtained.

The obtained EVOH water / alcohol solution was extruded in a strand form from a nozzle with a pore diameter of 4 mm into a coagulation liquid tank maintained at 5 ° C. consisting of 5% methanol and 95% water. Cutting with a cutter gave EVOH porous pellets having a diameter of 3.8 mm and a length of 4 mm and a moisture content of 45%.
After washing with 100 parts of water with respect to 100 parts of the porous pellets, the mixture was put into a mixed solution containing 0.032% boric acid and 0.007% calcium dihydrogen phosphate, and at 30 ° C. for 5 hours. Stir. Further, the porous pellets were dried for 12 hours by passing nitrogen gas having a temperature of 70 ° C. and a moisture content of 0.6% in a batch-type ventilated box dryer, and the moisture content was adjusted to 30%. Using a batch tower type fluidized bed dryer, drying was performed with nitrogen gas having a temperature of 120 ° C. and a water content of 0.5% for 12 hours to obtain pellets of the target EVOH composition. Such pellets contained 0.015 parts by weight (in terms of boron) and 0.005 parts by weight (in terms of phosphate group) of boric acid and calcium dihydrogen phosphate with respect to 100 parts by weight of EVOH. Moreover, MFR of this EVOH composition (A1) was 4.0 g / 10min (210 degreeC2160g).

The amount of 1,2-glycol bond introduced was calculated by measuring the ethylene-vinyl acetate copolymer before saponification with ¹ H-NMR (internal standard substance: tetramethylsilane, solvent: d6-DMSO). However, it was 2.5 mol%. In addition, “AVANCE DPX400” manufactured by Nippon Bruker Co., Ltd. was used for NMR measurement.

[ ¹ H-NMR] (see FIG. 1)
1.0 to 1.8 ppm: methylene proton (integrated value a in FIG. 1)
1.87 to 2.06 ppm: methyl proton 3.95 to 4.3 ppm: proton on the methylene side of structure (I) + unreacted 3,4-diacetoxy-1-butene proton (integral value b in FIG. 1) )
4.6 to 5.1 ppm: methine proton + proton on the methine side of structure (I) (integral value c in FIG. 1)
5.2 to 5.9 ppm: unreacted 3,4-diacetoxy-1-butene proton (integral value d in FIG. 1)
[Calculation method]
Since there are four protons in 5.2 to 5.9 ppm, the integral value of one proton is d / 4, and the integral value b is an integral value including the protons of the diol and the monomer. The integral value (A) of the proton is A = (b−d / 2) / 2, and the integral value c is an integral value including the protons on the vinyl acetate side and the diol side. Since the integral value (B) is B = 1− (b−d / 2) / 2 and the integral value a is an integral value including ethylene and methylene, the integral value (C) of one proton of ethylene is , C = (a−2 × A−2 × B) / 4 = (a−2) / 4, and the introduction amount of the structural unit (1) is 100 × {A / (A + B + C)} = 100 × Calculated from (2 × b−d) / (a + 2).

Moreover, the result of having similarly performed ¹ H-NMR measurement also about EVOH after saponification is shown in FIG. Since the peak corresponding to 1.87 to 2.06 ppm of methyl proton is greatly reduced, the copolymerized 3,4-diacetoxy-1-butene is also saponified into a 1,2-glycol structure. It is clear that

Polymerization example 2
An EVOH composition (A2) was obtained by the following method.
In Polymerization Example 1, the amount of methanol initially charged was 20 kg, and 210 ppm of t-butylperoxyneodecanoate (with respect to vinyl acetate) was added over 5 hours instead of acetyl peroxide, and 3,4-diacetoxy-1 -Polymerized while adding 4.5 kg in total of butene at 15 g / min, and carried out in the same manner except that boric acid was not added, and the introduction amount of structural units having 1,2-glycol bonds was 2.5 mol%. Thus, an EVOH composition (A2) containing 0.005 parts by weight of calcium dihydrogen phosphate (phosphate basis conversion) and having an MFR of 5.2 g / 10 min was obtained.

Polymerization example 3
An EVOH composition (A3) was obtained by the following method.
70 of 3,4-diacetoxy-1-butene, 3-acetoxy-4-ol-1-butene and 1,4-diacetoxy-1-butene instead of 3,4-diacetoxy-1-butene in polymerization example 1: The procedure is the same except that a 20:10 mixture is used. The amount of structural units having 1,2-glycol bonds is 2.0 mol%, the ethylene content is 38 mol%, and the boric acid content is 0.015 parts by weight. An EVOH composition (A3) containing (in terms of boron), 0.005 parts by weight of calcium dihydrogen phosphate (in terms of phosphate radical) and MFR of 3.7 g / 10 min was obtained.

  Separately, ethylene content having no 1,2-glycol structure in the side chain 38 mol% Saponification degree 99.5 mol%, MFR = 3.5 g / min (210 ° C. 2160 g), boric acid content 0.015 parts by weight An EVOH (A4) composition containing 0.005 parts by weight (in terms of boron) and calcium dihydrogen phosphate (in terms of phosphate group) was obtained.

Example 1
The EVOH (A1) obtained above is supplied to a single screw extruder having L / D = 28, an inner diameter of 40 mm, a set temperature of 220 ° C., and using a screw with a screw compression ratio of 3.4, a coat hanger die having a width of 450 mm. A single layer film was extruded from the substrate and cooled with a roll at 80 ° C. to obtain a 20 μm single layer film, which was evaluated in the following manner.

(Evaluation of surface smoothness)
The haze value of the film which applied the liquid paraffin to the surface of the EVOH film obtained above, and the film which was not applied was measured, and surface smoothness was judged.
○ [Haze when applying liquid paraffin]-[Haze when not applying] = 0
Δ ... 0 <[Haze when applying liquid paraffin] − [Haze when not applying] <0.2
X ... [Haze when applying liquid paraffin]-[Haze when not applying] ≧ 0.2

(Adhesive evaluation)
A general-purpose adhesive for dry lamination (main ingredient AD-329 manufactured by Toyo Morton Co., Ltd. and curing agent CAT-8B was blended at a weight conversion of 1: 1 and diluted with ethyl acetate to adjust to 15% by weight) on the EVOH film surface. Application and drying at 80 ° C. gave an adhesive layer of 0.5 g / m 2. On the same surface, CPP having a thickness of 60 μm was pressed at a pressure of 2 kg / cm 2 for 1 second and dried at 150 ° C., and the obtained film was further aged at 40 ° C. for 48 hours to obtain a multilayer film for evaluation. This was cut into a strip with a width of 15 mm, a peel test was performed at a pulling speed of 300 mm / min, and the following determination was made.
○ ・ ・ ・ Peel strength is 200 g / 15 mm or more Δ ・ ・ ・ Peel strength is 100 g / 15 mm or more and less than 200 g / 15 mm × ・ ・ ・ Peel strength is less than 100 g / 15 mm

Example 2
A film was prepared in the same manner as in Example 1 except that EVOH (A2) was used instead of EVOH (A1), and evaluation was performed in the same manner.

Example 3
A film was prepared in the same manner as in Example 1 except that EVOH (A3) was used instead of EVOH (A1), and evaluation was performed in the same manner.

Comparative Example 1
A film was prepared in the same manner as in Example 1 except that EVOH (A4) was used instead of EVOH (A1), and evaluation was performed in the same manner.

Example 4
The EVOH (A1) obtained above is supplied to a single screw extruder having L / D = 28, an inner diameter of 40 mm, a set temperature of 220 ° C., and using a screw with a screw compression ratio of 3.4, a coat hanger die having a width of 450 mm. A single layer film was extruded from the substrate and cooled with a roll at 30 ° C. to obtain a 60 μm single layer film.
The obtained film was simultaneously biaxially stretched 3.5 times in length and 3.5 times in width at 120 ° C. with a tenter type biaxial stretching machine to obtain a single layer stretched film having a thickness of about 5 μm. Evaluation similar to Example 1 was performed about the obtained film.

Example 5
A film was prepared in the same manner as in Example 4 except that EVOH (A2) was used instead of EVOH (A1), and evaluation was performed in the same manner.

Example 6
A film was prepared in the same manner as in Example 4 except that EVOH (A3) was used instead of EVOH (A1), and evaluation was performed in the same manner.

Comparative Example 2
In Example 4, a film was prepared in the same manner except that EVOH (A4) was used instead of EVOH (A1), and evaluation was performed in the same manner.

The evaluation results of Examples and Comparative Examples are summarized in Table 1.

[Table 1]

  The raw film for laminating of the present invention is composed of EVOH having a structural unit having a 1,2-glycol bond in the side chain, is excellent in adhesiveness and surface smoothness, and is useful as a packaging material for foods and medical products.

2 is a ¹ H-NMR chart before saponification of EVOH obtained in Example 1. FIG. 2 is a ¹ H-NMR chart of EVOH obtained in Example 1. FIG.

Claims (9)

A film for laminate raw material , comprising an ethylene-vinyl alcohol copolymer containing the following structural unit (1) and having an ethylene content of 20 to 60 mol% .

(Here, X is an alkylene group having 6 or less carbon atoms, R 1 to R 4 are hydrogen atoms, and n represents 0 or 1.)   The film for laminate raw material according to claim 1, wherein n of the structural unit (1) is 0.   The laminate raw film according to claim 1 or 2, wherein the structural unit (1) is introduced into a molecular chain of an ethylene-vinyl alcohol copolymer by copolymerization. The structural unit (1) is 0. Laminating raw film according to any one of claims 1 to 3, characterized in that it contains 1 to 3 0 mol%. Ethylene - vinyl alcohol copolymer is 3, 4 - diacyloxy - 1 - butene, in any one of claims 1 to 4, wherein the is obtained by saponifying a copolymer of vinyl ester monomer and ethylene The film for laminate raw materials described. Ethylene - vinyl alcohol copolymer is 3, 4 - diacetoxy - 1 - butene, any claims 1 to 5, characterized in that one obtained by saponifying a copolymer of vinyl ester monomer and ethylene The film for laminate raw materials described. The ethylene-vinyl alcohol copolymer converts the boron compound into an ethylene-vinyl alcohol copolymer in an amount of 0. The laminate raw film according to any one of claims 1 to 6, further comprising 0 0 1 to 1 part by weight. The film for laminate raw material according to any one of claims 1 to 7 , wherein the film is stretched in at least one axial direction. It is a single layer film, The film for laminated original fabrics in any one of Claims 1-8 characterized by the above-mentioned.

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