JPS62230840A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition giving a flexible packaging material having excellent flex fatigue resistance and high gas-barrier property, by compounding EVOH with a polyether-containing EVOH. CONSTITUTION:(A) 95-50pts.(wt.) of an ethylene-vinyl alcohol copolymer (EVOH) is compounded with (B) 5-50pts. of an ethylene-vinyl alcohol copolymer containing polyether component. The component B is e.g. a block copolymer of a polyether component and EVOH component, a polymer having a polyether component grafted as a branch polymer of EVOH, a polymer having a polyether-containing EVOH grafted as branch polymer of polyether, etc. The polyether component is constituted of oxypropylene units.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a resin composition that provides a packaging material that is flexible, has excellent bending fatigue resistance, and has excellent gas permeation resistance.

B. Prior art Ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) is widely known as a melt-moldable thermoplastic resin with excellent gas permeability, oil resistance, solvent resistance, fragrance retention, etc. , used for films, sheets, containers, etc. in various packaging fields.

However, since EvOH has the drawbacks of being hard, brittle, and lacking in flexibility, it is rarely used alone and is mainly used as a laminate with other thermoplastic resins. However, there is still no possibility that packaging materials with an EVOH layer may be damaged due to strong vibrations due to transportation, bending fatigue, etc.
Cracks and pinholes occur in the OH layer, making it impossible to maintain excellent gas permeability.

C0 Problems to be Solved by the Invention The present invention seeks to provide a resin composition that is flexible, has excellent bending fatigue resistance, and can be used as a packaging material having excellent gas permeation resistance.

Means for Solving Problem D2 As a result of intensive studies, the present inventors found that the above object can be achieved by blending an EVOH copolymer containing a polyether component into EVOH, and the present invention was completed.

Effects of E, @ Ming The packaging material made of the resin composition according to the present invention has excellent gas permeability, oil resistance, solvent resistance, and fragrance retention, and has superior performance to conventional gvo
Compared to the laminated packaging material using A, the flexibility and bending fatigue resistance are dramatically improved, and it is extremely useful as a flexible laminated packaging material of 1% in various packaging fields. It can be used widely.

Detailed Description of the F0 Invention The typical EVOH used in the present invention has an ethylene content of 20
The saponification degree of the vinyl acetate component is 95% or more, preferably 98% or more. If the ethylene content is less than 20 molar, the moldability will not necessarily deteriorate, but the gas permeability under high humidity will deteriorate. When the ethylene content exceeds 60 molti, the gas permeability resistance deteriorates significantly. Further, if the degree of saponification is less than 95%, although the flexibility increases, the gas permeability resistance deteriorates, which is not preferable. Furthermore, there is no problem in including other copolymerizable unsaturated monomers as long as the properties of EVOH are not impaired.

Note that the ethylene content of EVOH containing a polyether component of 60 moles refers to the ethylene content of EVOH excluding the polyether component.
It shows the content of ethylene in VOH.

The ethylene content and saponification degree of the EVOH containing a polyether component and the EVOH blended therewith can be arbitrarily selected within the above range, but the ethylene content and saponification degree may be equal or close to each other, for example, the difference in ethylene content may be 2
It is preferable that the difference in the degree of saponification is 0 molt or less, preferably 10 molt or less, and the difference in the degree of saponification is 34=m % or less, preferably 2 molt or less.

Examples of polyether components include those mainly composed of oxyalkylene units such as oxyethylene units, oxypropylene units, oxyethylene-oxypropylene units, and oxytetramethylene units. Ethylene-oxypropylene units are preferred. Furthermore, the polyether component contains polymethylene units, amide groups, urethane groups,
It may contain an ester group, a phenyl group, etc.

In the present invention, the weight ratio of the EVOH component to the polyether component of the EVOH copolymer containing the polyether component is such that the polyether component is 1% in order to impart flexibility and impact resistance.
0][i1i% or more, preferably 20% by weight or more, while the polyether component strength from the viewpoint of dispersibility or interaction when blending with EVO1 (!90tf'1
The following is a good size 1-(ke 80 Shigeso Hikari or less).

The method for producing an EVOH copolymer containing a polyether component in the present invention will be described in detail below.

The first type is one in which polyether and EVOH form a block copolymer, and when the polyether is expressed as P%EVOH by E, it is expressed as PE or h-nee PE. Such a block copolymer can be produced, for example, by the following method. A method in which vinyl acetate and ethylene are copolymerized in the presence of a polyether having a mercapto group at one or both ends, followed by saponification using a conventional method, or ethylene having a mercapto group at one end (one end) In the presence of vinyl alcohol copolymer, the terminal (
Examples include a method of combining a polyether having a polymerizable double bond at one or both ends.

Here, the polyether having a polymerizable double bond at the terminal has the general formula [where R is hydrogen or a methyl group, R and R are hydrogen or an alkyl group having 1 to 10 carbon atoms, and R3 is hydrogen or a carbon number 1
to 10 alkyl groups, alkyl ester groups (1 to 10 carbon atoms in the alkyl group), alkylamido groups (1 to 10 carbon atoms in the alkyl group), and n is an integer of 1 to 100. ] (Example: polyoxyethylene (meth)allyl ether, polyoxypropylene (meth)allyl ether, etc.), or general formula [where R, R, R, R Same as above]
meta) allyl ether type, or [but
R4 is hydrogen, an alkylkylene group having 1 to 10 carbon atoms, a substituted alkyref group, a phenylene group, a substituted phenylene group, m
represents an integer of 0 or 1 or more, respectively. (acrylic acid amide, polyoxypropylene (meth)acrylic acid amide, etc.), or general formula [however, R, R'', R2, R3, X, m, n f
(meth)acrylic acid ester-type products represented by ;l Same as above] (e.g. polyoxine ethylene (meth)acrylate, polyoxypropylene (meth)acrylate, etc.)
or a vinyl ether type compound (eg, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, etc.) represented by the general formula [where R1, R2, R3, X, m, and n are the same as above].

Next, in the second type, polyether is added as a branched polymer of E V OH in the form of a graft.

Such a graft copolymer can be obtained, for example, by copolymerizing ethylene and vinyl acetate with a polyether having a polymerizable double bond at the end, and saponifying the copolymer by a conventional method.

Furthermore, the third type is one in which gvoH is added in the form of a graft as a branched polymer of polyether.

Such a graft copolymer can be obtained, for example, by copolymerizing ethylene and vinyl acetate in the presence of a polyether having a mercapto group in its side chain, and then saponifying the copolymer. Although the methods described above are representative examples, the present invention is not limited to these methods.

EVO containing polyether thus obtained
) I-based copolymer and EVOH are pre-prepared.

The blending ratio varies depending on the type of polyether in the EVOH copolymer, the N* ratio, the addition form, and the required performance, but generally it contains 95 to 50 parts by weight of EVOH and polyether. EVOH copolymer is 5~
50 fi parts is preferred. As the blending method, known methods such as a method using a Pan Bali mixer and a melt blending method using a single-screw or twin-screw extruder can be adopted. In addition, during this blending, other additives such as antioxidants, ultraviolet absorbers, lubricants, plasticizers, antistatic agents, colorants, etc. may be added to the extent that the effects of the present invention are not impaired. .

The thus obtained uninvented resin composition can be easily molded by a well-known melt molding method, and can be molded into any molded product such as a film, sheet, tube, or bottle. Also other thermoplastics, such as polypropylene,
When used in a two- or three-layer or more laminated structure with polyethylene, polyethylene terephthalate, polyamide, polystyrene, etc., it is molded by known methods such as multilayer coextrusion, co-injection extrusion lamination, coating, etc. Furthermore, when using three or more layers, it is suitable to use the composition of the present invention as an intermediate layer.

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

G, Examples Examples 1 to 3 500 g of polyquine propylene allyl ether having a polymerizable double bond at both ends and having a molecular weight of 3000 (yPKA-5013, manufactured by NOF Gekiji Co., Ltd.) and 4 m of benzoyl peroxide were added in a volume of 1 kIA. The mixture was placed in a reaction tank equipped with a stirrer, and thioacetic acid was continuously added at room temperature at a rate of 139/hour for 3 hours while stirring. Unreacted thioacetic acid was then removed from the reaction system under reduced pressure at 30-45°C. Next, 100 y of methanol, 1.1 y of sodium hydroxide,
After stirring at 60° C. for 2 minutes under a nitrogen stream, acetic acid was added to neutralize excess sodium hydroxide. The mercapto group of the thus obtained mercapto-polyoquine propylene was titrated according to Step 2 and had the following properties: 6.56 x 10
When filtered at eq/11, both ends with double bonds were mercaptolyzed almost quantitatively.

Next, 14.5' fb of vinyl acetate and 31.9 g of mercapto-polyoxypropylene were charged into a polymerization tank with a capacity of 50p and equipped with an internal cooling coil and a stirrer, and after replacing the air in the polymerization tank with nitrogen, The temperature was raised to 60°C, and ethylene was charged to bring the pressure to 43~/d.

Next, a polymerization initiator 2,2'-azobis-(2,4-dimethylvaleronitrile) 149% dissolved in 300ml of methanol was added, and then 440ml of mercaptated polyoxypropylene was added. The polymerization reaction was carried out by adding at a rate of F/wait time for 4 hours. The polymerization rate of vinyl acetate was 42%.

The copolymerization reaction solution is then fed to a purging tower, methanol is introduced from the bottom of the tower, and unreacted vinyl acetate is removed from the top of the tower, followed by a saponification reaction using sodium hydroxide as a catalyst by a conventional method. was carried out. After thorough washing with acetone and water, the film was immersed in a dilute aqueous acetic acid solution and dried at 60 to 105°C under a nitrogen stream. The EVOH copolymer thus obtained is a block copolymer in which EVOH is added to both ends of polyoxypropylene, and its composition was analyzed by NMR, and the ethylene content was 30.8.
Molch, containing 11t31M' of polyoxypropylene! to%
, saponification degree of vinyl acetate component 99. It was lchi. Also, 190℃, 2160! ASTM D under i load conditions
The melt index (hereinafter referred to as M1) measured by the method of -1238-65T is 120. p/10 minutes.

Next, the copolymer (copolymer A) and the ethylene content 32.1
Morti, saponification degree of vinyl acetate component 99.5%%M10
．． A composition was obtained by blending EVOH (EVOHNul) of 6111/10 minutes at a constant ratio, and these were extruded into films, and the Young's modulus, bending fatigue resistance, and oxygen permeation amount of the films were measured.

Extrusion film formation was carried out using a film forming machine having an extruder and a T-die under the conditions of extrusion heating temperature of 180 to 220°C and T-die temperature of 215°C to obtain a film with a thickness of 15 μm.

Young's modulus was measured using a sample of the film that had been conditioned at 20°C and 65SRH for 7 days, and according to ASTM D-
According to 638, by autograph, 15μ speed 10
The test was carried out under conditions of 1/min.

The bending fatigue resistance test was carried out using a GELBOLLEX tester (Rigaku Kogyo W-kei). A 12 inch x 8 inch sample piece was made into a cylindrical shape with a diameter of 32 x n, and both ends were gripped. The initial grip interval was 7 inches, and the test was carried out at the maximum bending time. Add 1 twist to the gripping interval, and then repeat the reciprocating movement of the gripping operation using linear horizontal movement for the next 2”-in at a speed of 40 times/min under the conditions of 20°C and 65% R)I. carried out.

Oxygen gas permeation iiO measurement is Modern Cont
Using 0X-TRAN 100 manufactured by ro1, 20℃,
The test was carried out under the conditions of 65° RH, 20° C., and 85 SRH after 7 days of humidity control. The samples used for this measurement were samples in which the number of repeated reciprocating movements was varied in the bending fatigue resistance test.

These measurement results are shown in Tables 1 and 2.

Comparative Examples 1 to 2 In place of the resin compositions of Examples 1 to 3, s iJ ethylene containing i32.1 mole and a saponification degree of vinyl acetate component of 99.
5%, Ml 0.611/10 min EVOH (EV
OH floor 1) When using a single product (control example 2), ethylene content 3165 mol%, vinyl acetate content 99%
．． 26 using 6% EVOH (EVOHm2) alone
The same evaluation was conducted for the case (Comparative Example 2).

The results are shown in Tables 1 and 2.

Examples 4 to 6 with blank space below Table 1 A polymerization tank with an internal cooling coil and a stirrer, with a volume of 1 t5 (l), was charged with 25.0 y of vinyl acetate and 3.9 y of thioacetic acid, and the air in the polymerization tank was removed. After purging with nitrogen, the temperature was raised to 60°C, and ethylene was charged to set the pressure to 60 kf/-.Next, 100 g of the polymerization initiator 2,2'-azobisinbutyronitrile was dissolved in 11 methanol. Add,
Thereafter, a methanol solution of 1x thioacetic acid ('tg7) was added at 50%
The polymerization reaction was carried out by adding at a rate of 0 d/hour for 8 hours. The polymerization rate of vinyl acetate was 40-. Next, the copolymerization reaction solution was supplied to a purging tower, and unreacted vinyl acetate was removed from the top of the tower by introducing methanol from the bottom of the tower.
A saponification reaction was carried out in a conventional manner using sodium hydroxide as a catalyst.

Next, the saponified product was thoroughly washed with water, further washed with acetone, and dried under reduced pressure at 40°C. Polyoxypropylene allyl ether (NOF Unisafe PKA-5014) with a molecular weight of 11,500 and having a double bond of 2.5 liters and 20 ktt of dimethyl sulfoxide as a solvent were charged into the polymerization tank and the air in the tank was replaced with nitrogen. Thereafter, the temperature was raised to 60° C. and the homogeneous solution was subjected to rAa. Then 2.2'-7zobisin butyronitrile 100 II/! methanol solution of 500 tu
g was added and the reaction was carried out for 5 hours. Next, the reaction solution was added little by little into 20 (l) of acetone under stirring, and EVOH
The system co-arashi combination was precipitated. Then, after thorough washing with acetone, the sample was immersed in a dilute aqueous acetic acid solution, and then dried at 60 to 105[deg.] C. under a nitrogen stream. Thus obtained E
VOki copolymer is a block copolymer in which polyoxypropylene is added to one end of Evoi-+.
Its composition is polished rice analyzed by NMH-, ethylene content 44
．． The content of 7-propylene in the polio was 24% by weight, and the degree of saponification of the vinyl acetate component was 99.4%. Also, M
l was 230g/10 minutes.

Next, the copolymer (copolymer B) and the ethylene content 45.1
Morti, saponification degree of vinyl acetate component 99.5%, Ml
2.8. Sj/IO min 0EVOH (EVOHN12)
Example 1
A film was formed by extrusion in the same manner as in Steps 3 to 3, and the Young's modulus, bending fatigue resistance, and oxygen permeation amount of the film were measured. These measurement results are shown in Tables 3 and 4.

Control Examples 3-4 Instead of the resin compositions of Examples 4-6, the ethylene-containing i
45.1 molti, saponification degree of vinyl acetate component 99.5
%, MI 2.8 g/10 min OEVO) I (E
When using VO, HNa3) alone (Control example 3) j? Contains ethylene! 44.3 molti, degree of saponification of vinyl acetate component 99.3%, MI 9.5 g/10 molecules)
When EVOH (EVOH 4) is used alone (Control example 4)
) was also tested for U value. The results are also shown in Tables 3 and 4.

Table 3 Example 4 10/90 4.4
130#5 80/20 6.8
101 pair JIIJ3 EV011Nn3 single item 2
．． 8 151 Examples 7 to 9 In a polymerization tank with a capacity of 50.4 and equipped with an internal cooling coil and a stirrer, vinyl acetate of 11.0'f and polyoxy with a molecular weight of 3000 having polymerizable double bonds at both ends were placed. Propylene allyl ether (Unisafe PKA-5 manufactured by Nippon Oil & Fats Corporation)
013) 7.46 kls methanol 4.7 kp and polymerization initiator 2,2'-azobis-(2,4-dimethylvaleronitrile) 45. P was dissolved in 500 m/m of methanol and charged, the ethylene pressure was set to 37 kf/i,
Copolymerization was carried out at 60° C. for 6.8 hours. The polymerization rate of vinyl acetate was 40%. The copolymerization reaction solution is then supplied to a purging tower, and unreacted vinyl acetate is removed from the top of the tower by introducing methanol from the bottom of the tower, followed by a saponification reaction using sodium hydroxide as a catalyst in a conventional manner. did. After thorough washing with acetone and water, the film was immersed in a dilute aqueous acetic acid solution and dried at 60 to 105°C under a nitrogen stream. The thus obtained EVOH-based copolymer was obtained by adding polyoxypropylene as a branch polymer of EVOH in the form of a graft, and its composition was analyzed by NMR. Content 49! [%, degree of saponification of vinyl acetate component 99.4
%Met. Moreover, Ml was 0.511/10 minutes.

Next, the copolymer (copolymer C) with an ethylene content of 37.
8 molti, degree of saponification of vinyl acetate component 99.4 ti, Ml
1.3.9/10 minutes (7) EVOH (EVOHm5)
Compositions were obtained by blending the following in various proportions, and
A film was formed in the same manner as in No. 3, and the Young's 1r1, bending fatigue resistance, and oxygen permeation amount of the film having a thickness of 15 μm were measured. These results are shown in Tables 5 and 6.

Comparative Example 5 In place of the resin compositions of Examples 7 to 9, the ethylene content was 37.8 mole and the saponification degree of the vinyl acetate component was 99.4%.
, MI 1.391 IO min 0 EVOH (EVOH 5)
A similar evaluation was also conducted when using a single product.

The results are also shown in Tables 5 and 6.

Table 5 and below margin Examples 10 to 12 Sufficiently dehydrated poly(oxyethylene-oxypropylene) with a molecular weight of 3000 (Uniloop 75D manufactured by NOF ■)
E-60, oxyethylene/oxypropylene weight ratio 75/25) 4.5kf% methylene bis(4-phenylinocyanate) 480g, thioglycerol 6
4y and 36p of acetic acid were charged into a reaction tank with a capacity of 102 and equipped with a stirrer, and stirred at 80°C for 3 hours to synthesize a polyether having a mercapto group in the side chain.

Next, 55 g of vinyl acetate (14.5 kfs) and polyether having a thiol group in the side chain were charged into a polymerization tank with a capacity of 50 J and equipped with a stirrer and a cooling coil inside, and the air in the polymerization tank was replaced with nitrogen. Thereafter, the temperature was raised to 60°C, ethylene was charged, and the pressure was set to 4319/d. Next, a polymerization initiator 2,2'-7zobis-(2,4-dimethylvaleronitrile) 14y was added, and then a polyether having a thiol group in the side chain was added at a rate of 404 g/hour for 5 hours to carry out polymerization. did.

The polymerization rate of vinyl acetate was 39%.Next, the copolymerization reaction solution was fed to a purging tower, and unreacted vinyl acetate was removed from the top of the tower by introducing methanol from the bottom of the tower. A saponification reaction was carried out using sodium hydroxide as a catalyst. Then, after thorough washing with acetone and water, it was immersed in a dilute aqueous acetic acid solution, and then dried at 60 to 105°C under a nitrogen stream. The EVO thus obtained
The H-based copolymer is made by adding EVOH as a branched polymer of polyether in the form of a graft, and its composition, as a result of NMR analysis, shows that the ethylene content is 31.8 mol, and the weight of poly(diethylene-polypropylene) is 35 mol. %, and the degree of saponification of the vinyl acetate component was 99.3%. Also, MI is 1
It took 70,9710 minutes.

Next, the copolymer (copolymer D) used in Examples 1 to 3 had an ethylene content of 32.1 molt, a saponification degree of the vinyl acetate component of 99.5%, and an MIO, 61f! / 10 minutes EV
Compositions were obtained by blending OH (EVOHml) in various proportions, and these were extruded into films in the same manner as in Examples 1 to 3, and the Young's modulus, bending fatigue resistance, and oxygen permeation of a 15μ thick film were determined. It was measured.

These results are shown in Tables 7 and 8.

Control Examples 6-7 Instead of the resin compositions of Examples 10-12, ethylene-containing t
31.4 molti, saponification degree of vinyl acetate component 99.5%
, MI 1.2,! i+ / 10 minutes EVOH (E
When using VOHIl&I6) alone (Control Example 6), the ethylene content was 32.3 molti, the degree of saponification of the vinyl acetate component was 99.6s, and the MI was 3.5! l/10 min EVOH
(gVOHml) A similar evaluation was also carried out for the case where a single product (Control Example 7) was used. The results are also shown in Tables 7 and 8.

Table 7 Example 13 Using copolymer A shown in Examples 1 to 3, measurements were taken on a 5-layer laminated film of 3 types (inner layer/adhesive layer/intermediate layer/adhesive layer/outer layer) as a sample. . The film forming machine is an extruder for inner and outer layers,
One extruder for the intermediate layer, one extruder for the adhesive layer, and a T-die for the five layers.The molding temperature is the extruder for the inner and outer layers 160~22.
The temperature was 0°C, the extruder for the intermediate layer was 180-220°C, the extruder for the adhesive layer was 120-220°C, and the T-die was 225°C. The intermediate layer was made of 25 parts by weight of copolymer A and EVO shown in Control Example 1.
I ((h:VOHMal) 75 parts by weight blend,
The inner and outer layers are made of linear polyethylene containing 1-octene as a copolymer component, containing 3.6 mole of the copolymer component, and having an MI of 1.1/10, and the adhesive layer is made of maleic anhydride with a vinyl acetate content of 33% by weight. It is a modified ethylene-vinyl acetate copolymer (MI 2.0, 9/10 minutes) with an acid modification degree of 1.5 weight.

The thickness of the laminated film was 12 μm for the intermediate layer, 30 μm for each of the inner and outer layers, and 5 μm for each layer without adhesive.

Next, the bending fatigue resistance test and the oxygen gas permeation amount were measured in the same manner as in Practical Examples 1 to 3. The results are shown in Table 9.

Comparative Example 8 In Example 13, copolymer A and gVO were used as the intermediate layer.
Hml's 7'V7 Dorosuke, tete, EVOHNCL
A 1fJ film was obtained in the same manner as on the same side except that 1 single product was used, and the bending fatigue resistance test and oxygen gas permeation amount were measured. The results are shown in Table 90
Margin Procedure Amendment Document March 30, 1986

Claims (5)

[Claims] (1) Ethylene-vinyl alcohol copolymer 95-5
0 parts by weight and 5 to 50 parts by weight of an ethylene-vinyl alcohol copolymer containing a polyether component. (2) An ethylene-vinyl alcohol copolymer containing a polyether component and an ethylene-vinyl alcohol copolymer are
The resin composition according to claim 1, which is a block copolymer with a vinyl alcohol copolymer component. (3) The ethylene-vinyl alcohol copolymer containing a polyether component is
The resin composition according to claim 1, in which the vinyl alcohol copolymer is added as a branch polymer in the form of a graft. (4) The ethylene-vinyl alcohol copolymer containing a polyether component has the ethylene-vinyl alcohol copolymer component added as a branch polymer of the polyether in the form of a graft. Resin composition. (5) The resin composition according to any one of claims 1 to 4, wherein the polyether component is composed of oxypropylene units.