JPH06271736A - Polyvinyl alcohol resin composition - Google Patents

Abstract

PURPOSE:To improve the low-temp. flexibility, aging stability, etc., of a molded article made from the subject compsn. by compounding an oxyalkylene-contg. polyvinyl alcohol with nylon 11 or 12 or a polyester elastomer. CONSTITUTION:Vinyl acetate and a polyoxyalkylene (meth)allyl ether are copolymerized and saponified to give a polyoxyalkylene-contg. polyvinyl alcohol (A), which is compounded with nylon 11 or 12 or a polyester elastomer (B) to give the objective compsn. The ratio of the melt index of component A to that of component B is required to be in a range of 0.2-5; if the ratio is out of the range, then the both components cannot be mixed sufficiently with each other, giving the compsn. not having the necessary and sufficient flexibility.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyvinyl alcohol resin composition.

[0002]

2. Description of the Related Art Molded products of polyvinyl alcohol resin,
For example, a film is excellent in properties such as aroma retention, transparency, oil resistance, antistatic property, oxygen barrier property and heat retention property, and also has hydrophilicity, water solubility or water dispersibility, so that it can be used as a normal hydrophobic film. It can also be used for applications not suitable for a film of a polymer.

In particular, a molded product made of oxyalkylene group-containing polyvinyl alcohol has excellent flexibility as compared with a general molded product made of polyvinyl alcohol, and has an excellent advantage that it can be melt-molded without using a plasticizer. It is used for various purposes.

For the oxyalkylene group-containing polyvinyl alcohol, for example, the following various foreign applications have been made. For example, U.S. Pat. Nos. 1,971,662, 2,844,570 and 2,990,398 show oxyalkylene group-containing polyvinyl alcohols obtained by addition-reacting ethylene oxide with polyvinyl alcohol. U.S. Pat. Nos. 3,033,841 and 4,369,281 show an oxyalkylene group-containing polyalkylene glycol obtained by saponifying a polymer obtained by graft-polymerizing vinyl acetate in the presence of polyalkylene glycol. US Pat. No. 4,618,648
No. 4,675,360 discloses a copolymer of vinyl alcohol and poly (alkyleneoxy) acrylate, which copolymer can be injection-molded and extruded. It has also been shown that the material is water soluble and flexible.

Japanese Unexamined Patent Publication No. 59-1655408 discloses
A modified polyvinyl alcohol obtained by saponifying a copolymer of an unsaturated monomer containing an oxyalkylene group and vinyl acetate is shown. Various types of applications are listed in the publication, and molded articles are also mentioned as an example of the applications. JP-A-3-203932 filed by the present applicant discloses a method of melt-molding an oxyalkylene group-containing vinyl alcohol copolymer under substantially anhydrous conditions. The publication describes that molding is performed substantially without using a plasticizer, and extrusion molding or injection molding can be used as a molding method.

[0006]

Molded articles made of oxyalkylene group-containing polyvinyl alcohol exhibit excellent flexibility as described above, but it is difficult to say that they have sufficient flexibility at low temperatures. , Plasticizers such as glycerin, polyethylene glycol, polypropylene glycol have been added. However,
Such a plasticizer is detached over time, and it is difficult to maintain the initial flexibility for a long period of time. Further, when such a plasticizer is used, it has a drawback that smoke and bleeding phenomena occur during molding, which has been a long-standing concern among those skilled in the art. Therefore, there is a strong demand for a resin composition that has sufficient flexibility even at low temperatures, can retain the flexibility for a long period of time, and does not generate smoke or bleed during molding.

[0007]

However, as a result of intensive studies by the present inventors to solve such problems, oxyalkylene group-containing polyvinyl alcohol and (I) nylon 11 and / or nylon 12, (II) polyester It has been found that a resin composition composed of a polymer selected from elastomers meets such an object, and has completed the present invention. In the present invention, (I) nylon 11
And / or Nylon 12 or (II) polyester elastomer is used as a plasticizer and melt-blended with oxyalkylene group-containing polyvinyl alcohol to reduce the brittle temperature of the resin composition, thereby molding the resin composition. We have succeeded in maintaining the flexibility of a product at low temperature and maintaining this flexibility for a long time, and also excellent in the adhesiveness to other base materials, and eliminating smoke and bleeding phenomena during molding. Hereinafter, the present invention will be described in detail.

The oxyalkylene group-containing polyvinyl alcohol used in the present invention is typically vinyl acetate and polyoxyalkylene (meth) such as polyoxyethylene (meth) allyl ether and polyoxypropylene (meth) allyl ether. Copolymerized with allyl ether,
It is then obtained by saponification. In this case, the copolymerization ratio of the polyoxyalkylene (meth) allyl ether is 0.1 to 20 mol%, particularly 0.1 to 5 mol%, and the polyoxyalkylene condensation degree in the polyoxyalkylene (meth) allyl ether is 1 ~ 300, especially 3-50,
The proportion of oxyalkylene units in the entire oxyalkylene group-containing polyvinyl alcohol is preferably 3 to 40% by weight. This indicates that there is an optimum range for the degree of localization-delocalization of oxyalkylene units and the length of oxyalkylene units in the copolymer.

The degree of saponification of vinyl acetate units in polyvinyl alcohol containing oxyalkylene groups is 70 to 100.
Suitable is mol%, preferably 80 to 99 mol%. The melt index at 210 ° C. under a load of 2160 g is 0.1 to 100 g / 10 minutes, preferably 0.5 to
50 g / 10 min is suitable. In addition, as a copolymerization component, components other than polyoxyalkylene (meth) allyl ether, for example, α-olefin (ethylene, propylene, long-chain α-olefin, etc.), ethylenically unsaturated carboxylic acid monomer, (acrylate, methacrylate, acrylonitrile). , Methacrylonitrile, vinyl chloride, vinyl ether, etc.) in an amount of about 30 mol% or less. As the polymerization method for obtaining the oxyalkylene group-containing polyvinyl alcohol, a solution polymerization method is usually adopted, and a suspension polymerization method, an emulsion polymerization method or the like can be adopted depending on the case. As the saponification reaction, an alkali saponification method, an acid saponification method or the like is adopted.

In addition to the above, polyvinyl alcohols containing oxyalkylene groups include vinyl acetate, polyoxyethylene (meth) acrylate, and polyoxypropylene (meth).
Acrylate, polyoxyethylene (meth) acrylamide, polyoxypropylene (meth) acrylamide,
Polyoxyethylene (1- (meth) acrylamide-
1,1-Dimethylpropyl) ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamine, polyoxypropylene allylamine and other polyoxyalkylene allylamines, polyoxyethylene vinylamine, polyoxypropylene vinylamine and other polyoxys It can also be obtained by copolymerizing alkylene vinyl amine or the like and then saponifying. The oxyalkylene group-containing polyvinyl alcohol can also be obtained by reacting alkylene oxide with polyvinyl alcohol, or by polymerizing vinyl acetate with polyoxyalkylene glycol and subsequent saponification.

Examples of the polymer in the present invention include (I) nylon 11 (polyundecanamide, a condensation polymer of ω-aminoundecanoic acid), nylon 12 (a ring-opening polymer of laurinlactam) or (II) a polyester elastomer. Chosen from. Nylon 11 or Nylon 12 in the above
(Hereinafter abbreviated as nylon) is a load of 2160g, 21
Melt index (b ₁ ) at 0 ° C. is 0.5 to 1
00 g / 10 minutes, preferably 1 to 50 g / 10 minutes are suitable. However, the melt index (a) and (b ₁ ) of the oxyalkylene group-containing polyvinyl alcohol at a load of 2160 g and 210 ° C. is 0.2 ≦ (a) / (b ₁ ) ≦
Must be 5. If (a) / (b ₁ ) exceeds the specified range, the oxyalkylene group-containing polyvinyl alcohol and nylon cannot be sufficiently blended, and necessary and sufficient flexibility cannot be obtained. Such nylon may be copolymerized with other nylon, for example, nylon 6
-12 is mentioned.

The above-mentioned polyester elastomer is a polyester / polyether type block copolymer or aromatic dicarboxylic acid in which polyester of aromatic dicarboxylic acid and aliphatic glycol is a hard segment and poly (alkylene oxide) glycol is a soft segment. And a polyester / polyester type block copolymer having an aliphatic glycol polyester as a hard segment and an aliphatic polyester such as polylactone or poly (alkylene adipate) as a soft segment. Such a polyester elastomer is obtained according to a known method, wherein an aromatic dicarboxylic acid or its lower alkyl ester and an aliphatic glycol are esterified to form a polyester which is a hard segment, and then the polyester and a poly (alkylene oxide) which is a soft segment. It is produced by a method of melt-polycondensing glycol or polylactone or poly (alkylene adipate) to obtain a thermoplastic polyester elastomer.

As the aromatic dicarboxylic acid, terephthalic acid and its lower alkylene ester are mainly used. Others include isophthalic acid, phthalic acid and 2,5-
Norbonane dicarboxylic acid, 1,4-naphthalic acid, 1,5
Examples thereof include naphthalic acid, 4,4-oxybenzoic acid and lower alkylene esters thereof. Among them, dimethyl phthalate is particularly preferable from the viewpoints of easy availability of raw materials and high polyesterification rate. Examples of the aliphatic glycol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, and 1,6-hexanediol. Among them, 1,4-butanediol has good elastic properties. And is preferable.

As the poly (alkylene oxide) glycol, poly (tetramethylene oxide) glycol,
Poly (ethylene oxide) glycol, poly (propylene oxide) glycol, etc. molecular weight 1000-4000
Among them, poly (tetramethylene oxide) glycol having a molecular weight of 1000 to 2000 is particularly preferable because it shows good elastic properties. The weight ratio of the hard segment polyester to such poly (alkylene oxide) glycol is 10:90 to 90:10, preferably 20: 8.
0 to 80:20 is suitable. As a polylactone,
δ-valerolactone, ε-caprolactone, and their polylactone-forming derivatives. The weight ratio of the hard segment polyester to the polylactone is 10:90 to 90:10, preferably 20:80 to 8.
0:20 is suitable.

As the poly (alkylene adipate),
Examples thereof include poly (ethylene adipate), poly (diethylene adipate), poly (propylene adipate), poly (tetramethylene adipate), poly (hexamethylene adipate), and poly (neopentylene adipate). The weight ratio of the hard segment polyester to the poly (alkylene adipate) is 10:90 to 90 :.
A value of 10, preferably 20:80 to 80:20 is suitable.

Such a polyester elastomer has a load of 2
160 g, melt index (b ₂ ) at 210 ° C. is 0.1 to 100 g / 10 minutes, preferably 1 to
50 g / 10 min is suitable. However, the load is 2160 g,
The melt index (a) and (b ₂ ) of the oxyalkylene group-containing polyvinyl alcohol at 210 ° C. is 0.
It must be 2 ≦ (a) / (b ₂ ) ≦ 5. (A)
When / (b ₂ ) exceeds the specified range, the oxyalkylene-containing polyvinyl alcohol and the polyester elastomer cannot be sufficiently blended, and necessary and sufficient flexibility cannot be obtained. The blending ratio of the polymer in the present invention is such that the oxyalkylene group-containing polyvinyl alcohol / polymer is 99/1 to 50/50, preferably 95/5 to 6
It is 0/40.

As a blending method, a well-known method, that is, an extruder, a roll kneader, a Banbury mixer, or the like is melt kneaded and mixed. Further, it is possible to use a method in which the respective components are not melt-blended in advance but separately charged into a molding machine and directly melt-blended in the molding machine and then immediately melted or injection-molded. Such a resin composition,
Other polymers may be blended within a range that does not impair the gist of the present invention, or conversely, the above resin composition may be blended with other polymers. Further, various additives such as a plasticizer, a filler, a colorant and a stabilizer can be blended. A molded article comprising the resin composition thus obtained has good flexibility and stability over time at low temperatures, and also has excellent adhesiveness to other base materials, and causes smoke and bleeding phenomena during molding. It can be resolved.

In the above, the resin composition of the present invention and the substrate having excellent adhesion are, for example, polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer,
Examples thereof include ethylene-acrylic acid copolymers, ethylene-propylene copolymers, polypropylene, ionomers, and unsaturated carboxylic acid-modified polyolefins obtained by graft-polymerizing unsaturated carboxylic acids such as maleic anhydride with these polyolefins. When a molded product is obtained from the resin composition of the present invention, it is melt-molded. Examples of the melt molding method include an injection molding method, an extrusion molding method, and a transfer molding method. The extrusion molding includes blow molding, inflation molding, coextrusion molding, and extruder-molding.
John coating etc. are also included.

As the injection conditions, for example, a cylinder temperature of about 150 to 250 ° C., a mold temperature of about 10 to 100 ° C., and an injection pressure of about 500 to 2000 kg / cm ² are adopted. As the extrusion molding conditions, for example, it is preferable that the die temperature is set to about 150 to 250 ° C., and the screw compression part temperature is set to 5 to 30 ° C. higher than the discharge part temperature. The form of such a molded article is not particularly limited, and examples thereof include bottles (particularly bottles for agricultural chemicals), films, sheets, hoses, tubes, containers, bags, fibers, foams and the like. Further, in addition to the molded product, it is used for various applications such as hot melt adhesives, paper processing agents, and fiber processing.

[0020]

[Working] The resin composition of the present invention is (I) nylon 1
1 and / or Nylon 12 or a polymer selected from (II) polyester elastomer, and melt blending with an oxyalkylene group-containing polyvinyl alcohol, whereby the flexibility and aging stability of a molded article made of such a resin composition at low temperature To improve adhesion to other base materials, and eliminate smoke and bleeding phenomena during molding.

[0021]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to actual examples. Example 1 Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 300 Polyoxyethylene monoallyl ether (degree of condensation of oxyethylene is 15) Copolymerization ratio: 1.5 mol% Ratio of oxyalkylene units in the whole polymer: 1
7.6 wt% Saponification degree of vinyl acetate component: 95 mol% MI value: 23 g / 10 min

Nylon 11 Melting point: 190 ° C. MI value: 20 g / 10 min The above resins were fed at a blending ratio shown in Table 1 to a twin-screw extruder equipped with a brand die and extruded at a temperature of 210 ° C. to form pellets. A resin molded product was obtained. The physical properties of the obtained resin molded product were measured by the following methods. Moreover, the presence or absence of smoke and bleeding during the molding process was observed. The results are summarized in Table 1. The MI value (melt index value) was measured at 210 ° C. under a load of 2160 g using a melt indexer (nozzle: 2.095 mmφ × 8 mm) manufactured by Toyo Seiki Seisakusho. (The same applies below)

<Flexibility> The pellets obtained above were molded into a 3 cm × 15 cm × 2.5 mm plate-shaped molded product by an injection molding method, and the temperature was 20 ° C., 65% RH, −10 ° C., 0% R.
Each was left in H for 3 days. Under each of the conditions, one of the plate-shaped molded products was fixed with a vise, and the other end was pressed downward (θ = 45 °) and held in that state for 10 minutes.
After 10 minutes, the appearance of the molded product was observed. ◎ No change ○ It does not break until it reaches θ = 45 °, but cracks occur when it is held for 10 minutes △ Cracks occur before reaching θ = 45 ° (20 ° <θ <45 °) × θ = 45 ° Cracks occur at the front (θ <20 °) (θ represents the bending angle of the plate-shaped molded product from the horizontal state to the downward direction) << Adhesiveness >> Coextrusion method using low-density polyethylene and the pellets obtained above Thus, a two-layer film was prepared (using an acid-modified ethylene-vinyl acetate copolymer as an adhesive resin), and its peel strength was measured using Tensilon. Equipment used: Tensilon (manufactured by Orientec Co., Ltd.) Measurement conditions: Tensile strength 40 mm / min Chart speed 50 mm / min Sample film: Width 20 mm, length 50 mm

Example 2 An experiment was conducted according to Example 1 except that the resins shown below were blended at the blending ratios shown in Table 1. The results are summarized in Table 1. Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 500 Polyoxyethylene monoallyl ether (degree of condensation of oxyethylene is 10) Copolymerization ratio: 2.0 mol% Ratio of oxyalkylene units in the entire polymer: 1
5.4 wt% Saponification degree of vinyl acetate component: 90 mol% MI value: 7 g / 10 min Nylon 11 melting point: 190 ° C. MI value: 6 g / 10 min

Example 3 The resins shown below were blended at the blend rates shown in Table 1.
Other than that, the experiment was performed according to Example 1. The results are summarized
It shows in Table 1.Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 750 polyoxyethylene monoallyl ether (oxyethylene
The degree of condensation of benzene is 15) Copolymerization ratio of units: 2.0 mol% Ratio of oxyalkylene units in the entire polymer: 2
1.4 wt% Saponification degree of vinyl acetate component: 90 mol% MI value: 0.2 g / 10 minNylon 12  Melting point: 185 ° C. MI value: 0.5 g / 10 min

Example 4 An experiment was conducted according to Example 1 except that the resins shown below were blended at the blending ratio shown in Table 1. The results are summarized in Table 1. Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 900 Polyoxyethylene monoallyl ether (degree of condensation of oxyethylene is 10) Copolymerization ratio: 2.5 mol% Ratio of oxyalkylene units in the entire polymer: 1
8.6 wt% Saponification degree of vinyl acetate component: 91 mol% MI value: 0.1 g / 10 min Nylon 12 melting point: 185 ° C. MI value: 0.3 g / 10 min

Example 5 An experiment was conducted according to Example 1 except that the resins shown below were blended at the blending ratios shown in Table 1. The results are summarized in Table 1. Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 560 Polyoxyethylene monoallyl ether (degree of condensation of oxyethylene is 5) Copolymerization ratio: 4.0 mol% Ratio of oxyalkylene units in the entire polymer: 1
5.8 wt% Saponification degree of vinyl acetate component: 94 mol% MI value: 1 g / 10 min Nylon 6-12 Melting point: 220 ° C. MI value: 2 g / 10 min

Example 6 An experiment was conducted according to Example 1 except that the resins shown below were blended at the blending ratios shown in Table 1. The results are summarized in Table 1. Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 560 Polyoxyethylene acrylamide (degree of condensation of oxyethylene is 30) Copolymerization ratio: 1.0 mol% Ratio of oxyalkylene units in the entire polymer: 2
2.4 wt% Saponification degree of vinyl acetate component: 97 mol% MI value: 3.2 g / 10 min Polyester / polyether block copolymer polybutylene terephthalate / poly (tetramethylene oxide) glycol = 40/60 (weight ratio ) Melting point: 180 ° C. MI value: 5 g / 10 min

Example 7 The resins shown below were blended at the blending ratios shown in Table 1.
Other than that, the experiment was performed according to Example 1. The results are summarized
It shows in Table 1.Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 350 Polyoxyethylene vinyl ether (of oxyethylene
Condensation degree is 20) Copolymerization ratio of units: 2.0 mol% Ratio of oxyalkylene units in the entire polymer: 2
8.2 wt% Saponification degree of vinyl acetate component: 98 mol% MI value: 22 g / 10 minPolyester / polyether block copolymer  Polyethylene terephthalate / poly (tetramethylene
Xide) glycol = 25/75 (weight ratio) Melting point: 170 ° C. MI value: 25 g / 10 min

Example 8 An experiment was carried out according to Example 1 except that the resins shown below were blended at the blending ratios shown in Table 1. The results are summarized in Table 1. Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 490 Polyoxypropylene vinyl ether (degree of condensation of oxyethylene is 10) Copolymerization ratio: 3 mol% Ratio of oxyalkylene units to the entire polymer: 2
8.2 wt% Saponification degree of vinyl acetate component: 99 mol% MI value: 3.5 g / 10 min Polyester / polyether block copolymer polybutylene terephthalate / poly (tetramethylene oxide) glycol = 50/50 (weight ratio ) Melting point: 190 ° C. MI value: 5 g / 10 min

Example 9 An experiment was conducted in accordance with Example 1 except that the resins shown below were blended at the blending ratios shown in Table 1. The results are summarized in Table 1. Oxyalkylene group-containing polyvinyl alcohol Average degree of polymerization: 650 Copolymerization ratio of polyoxypropylene vinyl ether (oxyethylene condensation degree is 20) units: 1 mol% Ratio of oxyalkylene units in the entire polymer: 2
0.3 wt% Saponification degree of vinyl acetate component: 96 mol% MI value: 0.4 g / 10 min Polyester / polyester block copolymer Polyethylene terephthalate / ε-caprolactone = 6
0/40 (weight ratio) Melting point: 200 ° C. MI value: 0.5 g / 10 min

Comparative Example 1 An experiment was conducted according to Example 1 except that glycerin was used instead of nylon 11. The results are summarized in Table 1. Comparative Example 2 An experiment was conducted according to Example 1 except that nylon 66 was used instead of nylon 11. The results are summarized in Table 1. Comparative Example 3 An experiment was conducted according to Example 1 except that Nylon 11 was not used. The results are summarized in Table 1. Comparative Example 4 An experiment was carried out according to Example 6 except that the polyester / polyether block copolymer was not used. The results are summarized in Table 1.

[0033]

[Table 1]

[0034]

The resin composition of the present invention comprises a polymer selected from (I) nylon 11 and / or nylon 12 or (II) polyester elastomer, and melt-blended with polyvinyl alcohol containing oxyalkylene group Since it improves the flexibility and stability over time of a molded product made of such a resin composition at low temperature, further improves the adhesiveness with other base materials, and eliminates smoke and bleeding phenomena during molding processing. Is extremely advantageous.

Claims (2)

[Claims] 1. An oxyalkylene group-containing polyvinyl alcohol and (I) nylon 11 and / or nylon 1
2. Polyvinyl alcohol resin composition comprising a polymer selected from (II) polyester elastomers 2. A melt index (a) of polyvinyl alcohol containing an oxyalkylene group and a melt index (b) of a polymer at 210 ° C. under a load of 2160 g.
Is 0.2 ≦ (a) / (b) ≦ 5. The polyvinyl alcohol-based resin composition according to claim 1, wherein