JP2544753B2 - Polyvinyl chloride laminated structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention provides Tg on at least one side of a polyvinyl chloride substrate.
(Glass transition point) Saponified product of polyesteramide and ethylene-vinyl acetate copolymer with a temperature of 50 ° C or less (hereinafter referred to as EVOH)
And a polyvinyl chloride laminated structure having a mixture layer of

B. Conventional Technology Polyvinyl chloride has a wide range of uses as a resin with well-balanced properties among general-purpose resins. However, all properties cannot be satisfied by polyvinyl chloride alone. For example, when used in hollow containers for foods and non-foods, high gas barrier properties are required in fields where it is necessary to prevent oxidation of contents or retain scent. For vinyl chloride wallpaper, vinyl chloride leather, etc. made of soft vinyl chloride, the odor caused by the bleeding of the plasticizer,
It has the drawback that it is easily soiled and difficult to remove. Therefore,
In order to remedy the above drawbacks, EV is used as an outer layer of polyvinyl chloride.
It is known that forming an OH layer imparts high gas barrier properties, plasticizer bleed prevention properties, and oil resistance.

As a method of forming an EVOH layer on the outer layer of polyvinyl chloride, a method of laminating an EVOH film on polyvinyl chloride (Shokai 59-172927) or applying an EVOH solution to polyvinyl chloride and drying it to form an EVOH coating layer. The formation method (Japanese Patent Laid-Open No. 60-124661) and the like are known, and it is possible to form a coating having a comparatively thin film thickness, and it is easy to form a coating on a substrate having a complicated shape such as a hollow container. A solution coating method, in which a solution of EVOH dissolved in a solvent is applied to a substrate, has been drawing attention because it can be formed and a coating operation can be performed with a relatively simple device.

With the polyvinyl chloride layer using the solution coating method
When EVOH layers are laminated, they will not adhere at all unless an adhesive layer is provided on the intermediate layer. Polyurethane adhesives are mainly used as the adhesives used in such applications, but normally, the adhesive solution is applied to polyvinyl chloride serving as a base material and dried, and then the EVOH solution is applied and dried. This gives a laminated structure of EVOH and polyvinyl chloride. However, the process of applying and drying the adhesive solution and the EVOH solution respectively requires complicated equipment and is disadvantageous in terms of cost.

Therefore, if a solution obtained by mixing an adhesive with an EVOH solution is used, it is very useful in terms of cost by simplifying the coating and drying process of the adhesive and omitting the solvent of the adhesive solution. As a method thereof, Japanese Patent Publication No. 30600/1985 proposes blending polyethyleneimine with an EVOH solution. However, this method adheres strongly to polyolefin-based polymers, but hardly to polyvinyl chloride.

Further, JP-A-60-239233 discloses that polyvinyl chloride and EVOH
As the interlayer adhesive of the above, a laminate using a blend of vinyl chloride-vinyl acetate or an acrylic ester copolymer and a reactive polyurethane polymer is described, but this method also applies the adhesive to the EVOH layer side. However, there is a disadvantage in that a drying step is required if necessary.

In addition, USP4459400 (JP-A-60-144330) and U.S.P.
SP4481238 (Tokusho Sho-60-501312) describes the use of polyesteramide as an interlayer adhesive between EVOH layer and PET layer. Polyesteramide has excellent adhesiveness to polyvinyl chloride. ,Furthermore
There is no disclosure of laminating a mixture layer of EVOH and polyester amide and a polyvinyl chloride layer, and by doing so, a laminated structure having excellent adhesion can be obtained.

C. Problems to be Solved by the Invention The present invention is to provide a laminated structure in which polyvinyl chloride and EVOH are firmly adhered while simplifying the step of coating and drying the adhesive.

D. Means for Solving the Problems According to the present invention, the above object is to saponify a polyester amide having a Tg (glass transition point) of 50 ° C. or less and an ethylene-vinyl acetate copolymer on at least one surface of a polyvinyl chloride substrate. This is accomplished by providing a polyvinyl chloride laminate structure having a mixture layer having a weight ratio of 5:95 to 35:65.

E. More Detailed Description of the Invention The greatest feature of the present invention is that the mixture of polyesteramide and EVOH strongly adheres to the polyvinyl chloride layer.

The polyesteramide referred to in the present invention needs to have a Tg (glass transition point) of 50 ° C. or lower, preferably 40 ° C. or lower, particularly preferably 30 ° C. or lower. When Tg exceeds 50 ° C, not only the compatibility with EVOH decreases but also the adhesive strength with polyvinyl chloride and EVOH decreases.

Polyesteramide is a polymer composed of a reaction product of a diamine component, a diol component and a dicarboxylic acid component and having an ester repeating unit and an amide repeating unit in one polymer chain. The diamine component is composed of at least one diamine having about 2 to 14 carbon atoms and is preferably aliphatic, but aromatic diamine may be added within the range not departing from the spirit of the present invention. Suitable diamines include hexamethylene diamine, piperazine,
1-Aminoethylpiperazine, bisaminopropylpiperazine, 1,3-dipiperidyl propane, 1,4-cyclohexanebismethylamine, 1,2-ethanediamine, a mixture thereof and the like are included. The diol component is about 2
It consists of at least one diol containing up to 14 carbon atoms. Suitable diols include ethylene glycol, 1,4
-Butanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol,
Or a mixture thereof and the like are included.

The polyesteramide further comprises a dicarboxylic acid component. The dicarboxylic acid component consists of at least one dicarboxylic acid containing up to about 5 to 14 carbon atoms and is preferably aliphatic, but addition of an aromatic dicarboxylic acid within the scope of the present invention is not critical. Is also good. Suitable dicarboxylic acids are sebacic acid, azelaic acid, adipic acid,
A mixture thereof and the like are included.

The polyesteramide referred to in the present invention is synthesized by a method generally known in the art for producing a polyesteramide. Usually, it is produced by a melt phase polymerization method from a diamine component, a diol component and a dicarboxylic acid component in the presence of a catalyst (preferably a titanium compound). Examples include JP-A-60-144330, JP-A-61-501312, and the like. The polyesteramide used in the present invention is an ester component and an amide component in the polymer chain of 5:95 ~.
The resin is contained in a molar ratio range of 40:60, preferably 10:90 to 30:70. If the amount of the ester component is 5 mol% or less, the adhesive force with polyvinyl chloride is reduced, while if it is 40 mol% or more, the compatibility with EVOH is reduced.

EVOH used in the present invention has an ethylene content of 20 to 60 mol%,
Preferably 25 to 55 mol%, the degree of saponification of the vinyl acetate component is 90
% Or more, preferably 95% or more, ethylene content of 20
When it is at most mol%, the gas barrier property at high humidity will be lowered, or the water resistance will be lowered. On the other hand, when it is 60 mol% or more, sufficient gas barrier properties cannot be obtained, or the bleeding preventive property of the plasticizer decreases. . Further, when the saponification degree is 90% or less, the gas barrier property and the moisture resistance decrease.

EVOH is also a small amount of propylene, isobutene, α
An α-olefin such as octene, an unsaturated carboxylic acid or a salt thereof, a partial alkyl ester thereof, a complete alkyl ester thereof, a nitrile thereof, an amide thereof, an anhydride thereof,
It may contain a comonomer unit such as an unsaturated sulfonic acid or a salt thereof.

Regarding the blending ratio of polyesteramide and EVOH, if the blending ratio of polyesteramide is low, adhesion with polyvinyl chloride is poor and a satisfactory composite structure cannot be obtained. Sex decreases. Therefore, the blending ratio of the polyesteramide is in the range of 5 to 35% by weight, preferably 10 to 30% by weight, based on the total weight of the polyesteramide and EVOH.

The most effective method for providing the mixture layer of polyesteramide and EVOH on at least one surface of the polyvinyl chloride base material is to dissolve the polyesteramide and EVOH in a common solvent for these and apply the solution. Here, the common solvent is a monohydric alcohol such as methyl alcohol, ethyl alcohol, propyl alcohol or butyl alcohol, or 2 such as ethylene glycol or propylene glycol.
Polyhydric alcohols, trihydric alcohols such as glycerin, phenols such as cresol, phenols such as ethylenediamine and trimethylenediamine, acids such as formic acid, dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone, etc. The water-containing material and the like are used alone or in admixture of two or more. Particularly preferably used solvents are water-alcohol-based mixed solvents such as water-normal propyl alcohol, water-isopropyl alcohol and water-methyl alcohol.

The concentration of the mixed solution of polyesteramide and EVOH can be applied at any concentration, but normally, it is preferably about 2 to 20% by weight.

As a method for applying a solution of a mixture of polyesteramide and EVOH, any known method such as a roller coating method, a spray coating method, a dip coating method, or the like can be applied. One coated surface of the polyvinyl chloride base material,
Either two sides or the entire surface may be used.

After applying a mixed solution of polyesteramide and EVOH to a polyvinyl chloride substrate, drying is performed. Drying temperature is 30
It may be heated at a temperature of about 200 to 200 ° C., preferably about 50 to 150 ° C. for about 10 seconds to 10 minutes. The coating can be dried until the volatiles are almost eliminated, but the volatiles can be added to the coating to prevent cracking of the coating and to maintain the transparency and interlayer adhesion of the coating for a long period of time.
It is advantageous to leave 0.5-5% by weight.

In the present invention, a mixture of EVOH and polyesteramide may be appropriately blended with additives such as a weather resistance stabilizer, an antioxidant, a filler, a reinforcing agent (glass fiber, etc.), a colorant, a surfactant, and a soluble inorganic salt. You can

In the present invention, the film thickness (thickness after evaporation of the solvent) of the mixture layer of polyesteramide and EVOH applied to the polyvinyl chloride base material is practically about 0.5 to 20 μm. 0.5
If it is less than μ, sufficient gas barrier property or plasticizer bleeding prevention property is difficult to be exhibited.On the other hand, if it is more than 20 μ, it is necessary to perform operations such as increasing the number of coatings to obtain a film having a target film thickness, resulting in remarkable productivity. The problem arises that it will decrease.

The formation of the composite structure is not limited to solution coating and can be performed by a method called hot pressing or coextrusion. For example, forming a composite structure by pressing a molten blend film of EVOH and polyesteramide and a polyvinyl chloride film under heating, or by coextruding a mixture of EVOH and polyesteramide and polyvinyl chloride. You can also

When laminating a mixture of EVOH and polyesteramide on a polyvinyl chloride base material, the surface of the polyvinyl chloride base material may be previously subjected to corona discharge treatment or flame treatment in order to improve the adhesive strength.

In the present invention, polyvinyl chloride is polyvinyl chloride, other monomers copolymerizable with vinyl chloride (for example,
Vinyl acetate, acrylic acid ester, etc.), and the polyvinyl chloride base material may be any such as a film, sheet, hollow bottle, or tube.

The present invention exhibits significant effects when laminating a mixture of EVOH and polyesteramide to a plasticized polyvinyl chloride film or sheet containing a plasticizer, and this point will be described below.

Polyvinyl chloride moldings often contain a plasticizer, and in that case, the content of the plasticizer is often 25 to 55% by weight based on the total amount. Here, as the plasticizer, 20 ° C
A plasticizer that is liquid at, for example, dibutyl phthalate, di-
2-Ethylhexyl phthalate, di-isooctyl phthalate, di-iso-decyl phthalate, di-decyl phthalate, di-nonyl phthalate, di-lauryl phthalate, butyl lauryl phthalate, butyl benzyl phthalate and other phthalate plasticizers, tricresyl There are phosphate-based plasticizers such as phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, chlorine-containing plasticizers such as chlorinated paraffin, and plasticizers that are solid at room temperature, such as di-cyclohexyl phthalate and alcohol. There are phthalate plasticizers such as phthalic acid diesters having 13 or more carbon atoms, polyhydric alcohol plasticizers such as dipentaerythritol fatty acid ester, and trimet acid plasticizers such as trioctyl trimellitate. Ethylene content of these things is 20-60
EVOH having a mol% and a saponification degree of a vinyl acetate component of 90% or more, preferably 95% or more exhibits plasticizer resistance and plasticizer bleed prevention. Among the plasticizers, the former (plasticizer that is liquid at 20 ° C.) is a plasticizer having a particularly remarkable bleeding property, but the EVOH can also prevent extremely remarkable bleeding of these plasticizers. Above all, the ethylene content is 25
EVOH in the region of ˜55 mol% has very satisfactory properties and virtually no plasticizer permeability.

The plasticizer permeation resistance also gradually decreases with increasing ethylene content, and when it exceeds 60 mol%, when it is laminated on a soft polyvinyl chloride sheet or film, bleeding of the plasticizer to the surface gradually occurs. It is recognized and the stain resistance is also reduced. On the other hand, properties such as plasticizer permeation resistance are further improved as the ethylene content is reduced, but water resistance is poor in a region of less than 20 mol%, which is not preferable.

Polyvinyl chloride moldings (films, sheets, etc.) containing such plasticizers, laminated with a mixture of EVOH and polyesteramide, are used as wallpaper, desk mats,
It is preferably used for document holders, PVC leather, agricultural films, etc.

In addition to these uses, the laminate of the present invention can be used for foods, beverages, medicines, packaging materials for medical products, containers and the like. It is also possible to coat or laminate a mixture of EVOH and polyesteramide on a polyvinyl chloride base material, and then stretch and / or heat-treat it to obtain a desired molded article.

Further, if necessary, a moisture-proof layer can be formed on the EVOH-polyesteramide layer of the composite structure by vinylidene chloride resin coating, vinyl chloride-vinyl acetate copolymer coating, or the like. In addition to the composite structure, the composite material laminated on polyester, polyolefin or the like can be used as a packaging material for foods, beverages, medicines, medical treatments, containers or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. All percentages and parts are by weight unless otherwise specified. Also, Tg (glass transition point)
Was measured using a Perkin-Elmer DSC-2 differential scanning calorimeter.

F. Examples Examples 1 to 4 Polyesteramide (Tg: 20.5) composed of azelaic acid / cyclohexanedimethanol / piperazine = 0.50 / 0.09 / 0.41 (molar ratio; ester component: amide component = 18: 82)
℃) and ethylene content 32 mol%, saponification degree 99.5% EVOH in a weight ratio of 5:95, 10:90, 15:85, 20:80 10 parts of a mixture of 35% water, 65% n-propyl alcohol Mixed solvent containing 90
And added to each part and stirred at 70 to 80 ° C. for about 2 hours to obtain 4 kinds of transparent solutions. After cooling these solutions to a liquid temperature of 25 ° C, the solutions were applied by an applicator coating method to a polyvinyl chloride film 80μ containing 33 parts of the plasticizer dioctyl phthalate (DOP) and dried at 70 ° C for 10 minutes. Was performed to form a coating film of EVOH (film thickness 5 μ) having a volatile content of about 3%.

 Various performances of the composite structure are shown in Table 1.

Example 5 Azelaic acid / ethylene glycol / piperazine = 0.
50 / 0.13 / 0.37 (molar ratio; ester component: amide component = 2
6:74) polyester amide (Tg: -2.3 ° C) and EVOH with an ethylene content of 32 mol% and a saponification degree of 99.5%
10 parts of a mixture of 5:85 was added to 90 parts of a mixed solvent containing 30% of water and 70% of n-propyl alcohol, and stirred at 70 to 80 ° C for about 2 hours to obtain a transparent solution. Liquid temperature of this solution
After cooling to 25 ° C, the plasticizer dioctyl phthalate (DO
P) is applied to 80μ of polyvinyl chloride film containing 33 parts by the above-mentioned solution by an applicator coating method, and it is heated at 80 ° C for 5
EVOH with a volatile content of 1.5% (film thickness 2μ)
Was formed.

When the transparency of the composite structure was measured, the Haze degree was 6.8.
%, Indicating good transparency.

The oxygen permeability of the composite structure was measured under the condition of 20 ° C-65% RH, and it was 9.3cc / m ² · day · atm (EV
OH layer only).

Further, the composite structure polyvinyl chloride film and EVOH
When the T-type peel strength between the coat films was measured, it was 200 g / 15 m
It was m wide.

Example 6 Sebacic acid / neopentyl glycol / piperazine =
0.50 / 0.05 / 0.45 (molar ratio; ester component: amide component =
10:90) polyester amide (Tg: 23.3 ° C) and EVOH with an ethylene content of 44 mol% and a saponification degree of 99.6% have a weight ratio of 1
10 parts of the mixture of 0:90 were added to 90 parts of a mixed solution containing 30% of water and 70% of n-propyl alcohol, respectively, and stirred at 70 to 80 ° C. for about 2 hours to obtain a transparent solution. Liquid temperature of this solution
After cooling to 25 ° C, the plasticizer dioctyl phthalate (DO
P) is applied to 80μ of polyvinyl chloride film containing 33 parts by the above-mentioned solution by an applicator coating method, and it is heated at 80 ° C for 5
EVOH with a volatile content of 1.2% (film thickness 2μ)
Was formed.

When the transparency of the composite structure was measured, the Haze degree was 5.6.
%, Indicating good transparency.

Further, when the oxygen permeability of the composite structure was measured under the condition of 20 ° C.-65% RH, it was 18.2 cc / m ² · day · atm (E
VOH layer only).

Further, the composite structure polyvinyl chloride film and EVOH
When the T-type peel strength between the coat films was measured, it was 60g / 15mm
It was a width.

Comparative Examples 1 to 2 Various performances of the composite structure in which the mixing ratio of polyesteramide and EVOH is 2:98, 40:60 are shown by the same coating film forming method as shown in Examples 1 to 4. Shown in 1.

In Comparative Example 1, the Haze degree indicating transparency and the oxygen permeability indicating gas barrier property were comparable to those in Examples 1 to 4, but the T-type peel strength indicating adhesive strength was very small, which caused a practical problem. there were.

In Comparative Example 2, there was no problem in the adhesive strength and the transparency, but the gas barrier property was extremely lowered.

G. Effect of the Invention According to the present invention, a polyvinyl chloride laminated structure having excellent gas barrier properties, plasticizer bleeding prevention property, and pollution prevention property, and further, EVOH is strongly adhered to polyvinyl chloride as a base material is provided. Obtainable.

Claims (6)

(57) [Claims] 1. Tg on at least one side of a polyvinyl chloride substrate
The weight ratio of polyesteramide (glass transition point) below 50 ℃ and saponified ethylene-vinyl acetate copolymer is 5:95 to 3
Polyvinyl chloride laminate structure having a 5:65 mixture layer. 2. A polyesteramide having at least one repeating unit of a diamine component having 2 to 14 carbon atoms, at least one repeating unit of a diol component having 2 to 14 carbon atoms, and a dicarumbonic acid component having 5 to 14 carbon atoms. The polyvinyl chloride laminated structure according to claim 1, which comprises at least one repeating unit of the above, and contains the ester component and the amide component in the polyesteramide in a molar ratio of 5:95 to 40:60. . 3. A saponification product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, and a saponification degree of a vinyl acetate component of 90.
The polyvinyl chloride laminated structure according to claim 1, which has a content of at least%. 4. The polyvinyl chloride laminated structure according to claim 1, wherein the film thickness of the mixture layer of the polyesteramide and the saponified product of the ethylene-vinyl acetate copolymer is 0.5 to 20 μm. 5. The polyvinyl chloride laminated structure according to claim 1, wherein the polyvinyl chloride substrate is a substrate containing a plasticizer. 6. A mixture layer of polyesteramide and a saponified product of ethylene-vinyl acetate copolymer, which is obtained by coating a mixed solution of a polyesteramide and a saponified product of ethylene-vinyl acetate copolymer and drying. The polyvinyl chloride laminated structure according to item 1.