JPH0333147A - Aqueous emulsion composition of vinylidene chloride resin - Google Patents

Abstract

PURPOSE:To prepare an aq. emulsion compsn. of a vinylidene chloride resin giving a film excellent in the transparency and antiblocking, slip and gas-barrier properties by compounding an aq. emulsion of a vinylidene chloride resin with a specific aq. emulsion of a resin having a very small particle diameter in a specified compounding ratio. CONSTITUTION:An aq. emulsion (A) of a vinylidene chloride resin having a mean particle diameter of 0.05-0.3mum is compounded with an aq. emulsion (B) of a resin having a glass transition paint of 50-150 deg.C and a mean particle diameter of 0.01-0.06mum in such an amt. that the solid content of B is 0.02-2wt.% based on that of B. The mean particle diameter of B is always less than that of A. The resulting compsn. is useful for packaging Vienna sausages, tobaccos, snacks, etc., and for forming a gas-barrier film on a surface of paper.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an aqueous vinylidene chloride resin emulsion composition that provides a film with excellent gas (particularly oxygen and water vapor) barrier properties, transparency, and blocking resistance. .

This composition can be used to form gas barrier films on the surfaces of plastic packaging materials and paper for Wiener sausages, cigarettes, snack foods, etc., or to form waterproof films on the floors and balconies of concrete buildings. used.

[Prior art]

The surface of a hose mainly made of regenerated cellulose used for packaging processed meat products such as sausages is coated with an aqueous vinylidene chloride resin emulsion and dried to form a film with excellent gas barrier properties and transparency. (Japanese Unexamined Patent Publication No. 119084/1984, 51-
No. 119085, Special Publication No. 49-6808, No. 52-1
No. 6490, No. 60-53055, FP 12540
25).

In addition, there are mayonnaise containers in which a polyvinylidene chloride film is formed on the surface of a hollow polyethylene container, and packaging films for cigarettes and foods in which a polyvinylidene chloride film is formed on the surface of a polypropylene film or polyester film (4' J Publication No. 47-43628, 4
No. 9-18632, No. 51-8991, No. 60-82
No. 54) is also known.

The first function required of the film obtained from the aqueous vinylidene chloride resin emulsion (aqueous component) for this purpose is gas barrier properties, and the second is transparency. Board properties such as adhesion to the substrate surface to which the aqueous emulsion is applied, printability to the coating surface, coating properties, blocking resistance, and slipping properties are also required.

Gas barrier properties are necessary to protect food from deterioration and spoilage from oxygen and water vapor, and transparency is required because the food inside the film bag or container must be clearly visible from the outside.

The gas barrier properties and blocking resistance of the vinylidene chloride resin film depend on the crystallinity of the vinylidene chloride resin, and generally the higher the content ratio of vinylidene chloride in the resin, the better. However, if the vinylidene chloride content is too high, the storage stability and film-forming ability of the aqueous emulsion of vinylidene chloride resin obtained by emulsion polymerization will decrease. is 78 to 96% by weight, mostly 86 to 94% by weight, and in order to obtain a higher crystalline one, seed polymerization (% Kosho No. 60-8254) or polymerization with a high vinylidene chloride content is required. By blending a resin emulsion with a resin emulsion having a normal content (Japanese Patent Publication Nos. 60-45648 and 62-59724), storage stability is achieved.

However, these latter highly crystalline aqueous emulsions are complex and costly to manufacture. Furthermore, in order to improve the crystallinity of the vinylidene chloride copolymer, the monomers to be copolymerized are limited to those having a low molecular weight, such as acrylonitrile, methyl methacrylate, and acrylamide.

In addition, in the case of an aqueous vinylidene chloride resin emulsion containing a normal amount of vinylidene chloride, after being applied onto a film or container, it is heated and forced dry, and furthermore, in order to promote the crystallization of the film, a 40 to 120% Generally, the aging treatment is carried out at 4 degrees Celsius, and the film is required to have anti-blocking and slip properties for the purpose of storing the wound film, supplying and discharging the film, and storing the dried container. Ru.

[Problem to be solved by the invention]

In order to improve the blocking resistance and slipping properties of a film formed from an aqueous vinylidene chloride resin emulsion, it has been proposed to blend 0.01 to 0.11% silica powder into an aqueous vinylidene chloride resin emulsion. ing. However, it is often difficult to uniformly mix the silica powder into the emulsion, and the transparency of the film tends to decrease.

An object of the present invention is to provide an aqueous vinylidene chloride resin emulsion composition that exhibits no or very little decrease in transparency and provides a film with excellent anti-blocking properties, slip properties, and gas barrier properties. shall be.

[Specific means to solve the problem]

In order to achieve the objective, in the present invention, in place of silica powder, 0.02 to 2% of the non-film-forming micro resin aqueous emulsion (B) is added to the vinylidene chloride resin aqueous emulsion (A) for film matrix formation. By blending the vinylidene chloride resin aqueous emulsion (A) in a proportion of The slippery microemulsion (B) particles made it possible to improve the slipping properties and blocking resistance of the film.

That is, the present invention provides an aqueous vinylidene chloride resin emulsion (A) with an average particle size of 0.05 to 0.3 microns, a glass transition point of 50 to 150°C, and an average particle size of 0.01 to 0.
．． 06 micron resin aqueous emulsion (B) (A
An aqueous vinylidene chloride resin emulsion composition in which the resin solid content of the emulsion (B) is blended in a ratio of 0.02 to 2% by weight to the resin solid content of the emulsion (B) [However, ( The average particle size of the resin in the emulsion B) is smaller than the average particle size of the resin in the emulsion (A). ].

Emulsion of component (A) The vinylidene chloride resin aqueous emulsion of component (A) can be formed into a film at room temperature, and the average particle diameter of the resin particles is 0.05 to 0.a microns.

Such an emulsion can be prepared, for example, by mixing a vinyl monomer mixture of 78 to 96% by weight of vinylidene and 22 to 4% by weight of other vinyl monomers in water in which an anionic emulsifier and/or a nonionic emulsifier has been fermented. It is obtained by emulsion polymerization at 40 to 65°C using a water-soluble catalyst such as sulfate. Emulsion polymerization can be carried out by ordinary one-stage polymerization or by
A seed polymerization method such as that described in Japanese Patent No. 54 may also be used.

Other vinyl monomers include, for example, vinyl salts, alkyl acrylates, alkyl methacrylates, acrylonitrile, methacrylonitrile, vinyl esters (such as vinyl acetate, vinyl propionate, etc.), vinyl ethers (e.g., vinyl methyl ether and evavinyl methyl ether). ,
Vinyl ethyl ether′! 4) Acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, salts of these six acids such as sodium, potassium, ammonium, etc., as well as acrylamide, methacrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, N- Methyloracrylamide, N-ethanolacrylamide, N-bronoquinolacrylamide, N-methylolmethacrylamide, N-ethanolmethacrylamide, N-methylolmaleimide, N-methylolmaleamide, N-methylolmaleamic acid,
N-methylolmaleamic acid ester, N-alkylolamide of aromatic hinylcarboxylic acid, methylol-p
-Vinylbenzamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-isopropoxymethylacrylamide, N-impropoxymethylmethacrylamide, N-butoxymethylacrylamide, N-butoxymethylmethacrylamide, N-imbutoxy Examples include methylacrylamide, N-imbutoxymethylmethacrylamide, and the like.

Furthermore, examples of the nonionic emulsifier include polyoxyethylene alkyl allyl ether, and as a representative example, polyoxyethylene nonyl phenyl ether with a polyoxyedelene oxide added thereto is preferably 9 to 40 moles.

Anionic emulsifiers include sulfates of higher aliphatic alcohols such as sodium lauryl acid, and dialkyl sulfosuccinates.

Micro resin aqueous emulsion as component (B) The micro resin aqueous emulsion as component (B) has a glass transition point (T
g) is +50°C or higher, and the average particle diameter of the resin is 0.
01~o, o6 micron. It is important for the resin particle size of this microemulsion to be smaller than the resin particle size of the emulsion of component (A) in terms of the transparency of the resulting film. Moreover, the Tg of this resin particle is 5
A high temperature of 0° C. or higher is necessary for the blocking resistance of the film.

Unlike conventional anti-blocking agents such as silica powder, it is easy to mix and disperse, and has good miscibility with the resin of the IJ Lux (4) component of the film, so it does not make the film glossy or reduce transparency. .

The aqueous resin emulsion of component (B) forms islands in the film obtained from the composition or is present on the surface layer of the film, imparting blocking resistance or slipping properties to the film, and (A When the large resin particles of component () form a continuous film, the micro resin particles of component (B) enter the voids between the resin particles of component (A) and do not reduce the transparency of the film. Therefore, it has a kind of resin filler function.

This micro resin aqueous emulsion uses 0.3 to 5% by weight as a vinyl monomer component for emulsion polymerization of vinyl monomers having polar groups such as acrylic acid, itaconic acid, acrylamide, hydroquine ethyl methacrylate, and glycidyl acrylate. This may also have a positive effect on the printability of the film.

Examples of vinyl monomer compositions to be emulsion polymerized are as follows.

(a) Vinyl acetate, ethyl methacrylate, vinyl chloride,
-vinyl monomer selected from n-7'lopyl methacrylate, styrene, α-methylstyrene, acrylonitrile, methyl methacrylate, etc. 55 to 100% by weight, (b) 2-ethylhexyl acrylate, n acrylate・
Butyl, ethyl acrylate, isopropyl acrylate,
0 to 40% by weight of soft vinyl monomers selected from 2-ethylhexyl methacrylate, acrylic 51n-propyl, n-butyl methacrylate, vinylidene chloride, ethylene, butadiene, etc. e→ Other vinyl monomers 0 to 10% Weight 1%.

Other vinyl monomers include a, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride, etc.
β-unsaturated carboxylic acids; monomers with functional groups such as crotonic acid, vinyl sulfonic acid, monomethacryloxyethyl phosphate, hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, methacrylamide, methylolated acrylamide, fumarmaleimide, etc. Can be mentioned.

The non-vinyl monomer in (a) is one whose homopolymer of vinyl monomer has a glass transition point exceeding 30°C,
The soft vinyl monomer ← is a monomer whose homopolymer of vinyl monomer has a glass transition point of 20° C. or lower.

The selection and amount of these monomers to be used are selected so as to obtain the desired glass transition point of the resin.

This microresin aqueous emulsion (B) can be obtained by emulsion polymerization of vinyl monomers, for example, by the method described in Japanese Patent Publication No. 62-28187. The polymerization is carried out by pre-adding 030-50% of water with 20-50% of anionic emulsifier and 10-50% of non-ionic emulsifier, and separately preparing a pre-emulsion from vinyl monomer, remaining water and remaining emulsifier. This is conveniently carried out by adding the pre-emulsion to a solution heated to 50-90°C over a period of 1-3 hours. The reaction mixture is stirred and the initiator is added at 1-5% in parallel with the emulsion addition.
It is added in the form of an aqueous solution. After adding 1 more layer of gold body mixture
Post-stir at 70-90°C for ~3 hours. If the monomer mixture is added to a solution containing the total amount of water and an emulsifier, it is also possible to obtain a synthetic resin dispersion consisting of extremely fine particles suitable for impregnating and priming with penetrating action. There are no mandatory conditions for adding the emulsion to prepare a dispersion of fine particles.

This microresin aqueous emulsion may be a room temperature crosslinking type resin aqueous emulsion, a self-heating crosslinking type, or a non-crosslinking type.

(Composition) Component (A) of the resin aqueous emulsion composition of the present invention and (
The blending ratio of component B) is the resin solid content ratio, and component CB) is (
A) 0.02 to 2% by weight of component, preferably 0.05 to 2%
Blend at a ratio of 0.8% by weight. Unless it is blended in an amount of 0.02% by weight or more, no improvement in the blocking resistance and slipping properties of the film can be expected. On the other hand, adding a large amount of component (B) is not preferable because it reduces the gas barrier properties of the film.

[Examples, etc.]

Next, preparation examples, examples, and comparative examples of aqueous emulsions will be given for further details. "Parts" and "%" described in these examples are based on weight unless otherwise specified.

Manufacturing side example 1 of vinylidene chloride resin aqueous emulsion Vinylidene chloride 92g Methyl acrylate 4 parts Acrylic R 1 part Acrylonitrile 3 parts Alkyl sulfonate soda salt 2 parts Neelex C1) Potassium persulfate 0.3 parts Avenous water 1 part There were 113 copies.

The minimum film forming temperature of this product is 16°C, and the average resin particle size is 0.
It was 1μ.

Example 2 Vinylidene chloride 91 parts, methyl methacrylate 8 parts, itaconic acid 0.5 parts, N-methylolacrylamide
A vinyl monomer mixture consisting of 0.5 part was emulsion polymerized in the same manner as in Example 1 to form a film at a temperature of 18°C and a resin particle size of approximately 0.0.
An 8 μm vinylidene chloride resin aqueous emulsion was obtained.

Manufacturing side example 3 of micro resin aqueous emulsion Temperature controller, anchor type stirrer, reflux condenser, supply container,
The following raw materials were charged into a reaction vessel equipped with a thermometer and a nitrogen inlet tube.

Water 275 parts 35% aqueous solution of sodium lauryl sulfonate (anionic emulsifier) 25 parts 20% solution of p-nonylphenol (nonionic emulsifier) (7) reacted with 25 moles of ethylene oxide 10 parts Mixture of the following as feed ■ was used.

Water 200 parts 35% solution of the above anionic emulsifier 25 parts Styrene 25 parts Methyl methacrylate 312 parts n-butyl acrylate
52 parts acrylamide 5
2.5 parts of potassium persulfate in 85 parts of water as feed
A solution of 50% was prepared.

After replacing the inside of the reactor with nitrogen gas, the feed material is added to the charge.
was added and the mixture was heated to 90°C. Then 10% of the feed ■ is injected into the reactor, then uniformly in parallel over 3 to 3.5 hours the remaining feed! and ■ were supplied to the reactor. After the feed was held at 90° C. for >1.5 hours, the reactor was cooled to room temperature. The pH of the dispersion was adjusted to 6 to 7.5 with aqueous ammonia, and the solid content was 40% by weight.
A microresin aqueous emulsion with a pg of 71.5°C and an average particle size of 0.03μ was obtained.

Examples 4 to 6 Micro resin aqueous emulsions shown in Table 1 were obtained in the same manner as in Example 3, except that the type of vinyl monomer and the composition were changed as shown in Table 1.

(Margins below) Table * For comparison 1. Keiho Mizusawa Chemical Co., Ltd.'s fine powder silica "trade name Pm2O3" average particle size 2.8±0.5 (catalog value).

Polymer resin emulsion test method JE1 101-1988 Glass transition point: Based on differential analysis method.

Equipment name Differential thermal analyzer manufactured by DuPont Measuring conditions Roaring speed 0°C/min Examples 1 to 7, Comparative Examples 1 to 7 The resin aqueous emulsions and silica powders of Examples 1 to 6 were mixed in the proportions shown in Table 2. Various film-forming resin aqueous emulsion compositions (coating compositions) were obtained.

The coating film properties of each of the obtained coating compositions were tested by the following method. The results were as shown in Table 2.

(1) Anti-blocking Polypropylene biaxially stretched film with a wall thickness of 60 μm (manufactured by Yufhi Sansho Co., Ltd.) Apply the dispersion so that the K1 dry coating needle becomes 5t/-, and dry at 100°C for 2 minutes. after, then 1
After aging at 00°C for 30 seconds, the coated surfaces of the resulting films were stacked together, and a load of 250f/- was applied and treated at a temperature of 40°C for 24 hours.The adhesion of the coated surfaces was examined and the following It was evaluated as follows.

A: The coated surfaces peel off from each other without any resistance.

B: After rubbing lightly with your fingertips 2.3 times, peel off gently.

C: There is some resistance, but it peels off without damaging the coated surface.

D: There is resistance when peeling off, causing scratches on the coated surface.

(2) Slip property The coated surfaces of the coated and dried films obtained in (1) were overlapped and pressed with fingers to examine the slip properties, and evaluated using the following criteria.

A...It slides without any resistance.

B...Slides with almost no resistance.

C: It slips, but there is some resistance.

D: There is considerable resistance and it is difficult to slip.

(3) Heat water whitening resistance.

Polyamide film (manufactured by Uniteca) with a wall thickness of 15μ,
Apply the dispersion so that the dry coating amount is 5r/nl,
After drying at 100° C. for 3 minutes, the film was immersed in hot water at 95° C. for 30 minutes, and the degree of whitening and deterioration of the film taken out was examined and evaluated as follows.

A: Transparent B: Pale blue coloration C: Blue-white coloration D---°-whitening (4) Obtained from oxygen barrier property (1) For the coated film, an additional 100
After aging treatment at ℃ for 30 seconds, oxygen permeability measurement + A position (0X-Tran Zo manufactured by MoCoN).

The oxygen barrier property was measured using a mold) under the conditions of 20° C. and 100% relative humidity (RH).

The units of evaluation values are as follows.

cc/m", 24 hr, 20°C, 100% RH (5) Haze (JIS K6717) The haze (degree of haze) was measured for a stack of 10 polypropylene biaxially stretched film coatings obtained in (1). .

(Margin below)

Claims (1)

[Scope of Claims] 1) A vinylidene chloride resin aqueous emulsion (A) with an average particle size of 0.05 to 0.3 microns, a glass transition point of 50 to 150°C, and an average particle size of 0.01 to 0.3 μm. 0.06 micron resin aqueous emulsion (
B) is based on the resin solid content of the emulsion of (A),
An aqueous vinylidene chloride resin emulsion composition in which the emulsion (B) has a resin solid content of 0.02 to 2% by weight. [However, the average particle size of the resin in the emulsion (B) is (
It is smaller than the average particle size of the resin in the emulsion A). ]