JPS61215612A - Plastisol composition - Google Patents

Abstract

PURPOSE:To improve markedly the stability of viscosity with time of a plastisol composition, by mixing a vinyl chloride resin usually used for plastisol with a polymer obtained by polymerizing a specified monomer in the presence of low-melting vinyl halide polymer particles to form coated particles. CONSTITUTION:The following is used as a resin which is mixed with the mentioned vinyl chloride resin for plastisol. Polymer particles obtained by polymerizing a monomer containing at least 30wt% vinyl halide to form polymer particles of an average particle diameter of 10-150mu, polymerizing 10-150pts.wt. monomer containing at least 60wt% methyl methacrylate in the presence of 100pts.wt. said polymer particles to form coated polymer particles and drying the formed coated particles. As a monomer for said polymer particles, a vinyl halide such as vinyl chloride or a mixture thereof with a monomer (e.g., vinyl acetate) which can lower the melting temperature of a vinyl halide resin is used. As monomers for polymerization for coating, those copolymerizable with methyl methacrylate, such as acrylic acid can be used in addition to methyl methacrylate.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a plastisol composition, and more particularly to a plastisol composition that does not impair the oral stability of viscosity and has excellent low-temperature processability. .

(Prior art) Plastisol compositions currently widely used industrially have a basic composition of a vinyl chloride resin for plastisol with an average particle size of 0.01 to 10 μm, a plasticizer for this resin,
Furthermore, if desired, it contains a vinyl chloride-based admixture resin having an average particle size of 20 to 150 microns, a filler, a pigment, a heat stabilizer, a blowing agent, a diluent, and the like. The characteristic of this processing is that it is shaped at room temperature.

This is heated to 160 to 250°C to melt and homogenize the vinyl chloride resin and plasticizer, and then cooled to obtain a product. In applications where plastisol is applied to substrates with poor heat resistance such as fibers, compositions that melt uniformly at lower temperatures are required, and vinyl chloride-vinyl acetate copolymer resins are used, and resins with strong dissolution are required. Although it is common to incorporate plasticizers with strong properties into plastisol compositions, low-temperature processability and oral stability of the composition's viscosity are contradictory, which significantly limits the scope of use of plastisol compositions.

(Problems to be Solved by the Invention) As a result of intensive research in order to solve the above-mentioned drawbacks, the present inventors have found that a specific monomer is coated and polymerized on vinyl halide polymer particles having low-temperature melting properties. It has been discovered that the oral stability of the viscosity of plastisol compositions obtained by mixing this polymer with ordinary vinyl chloride resin for plastisols can be significantly improved, and based on this knowledge, the present invention was completed. It has arrived.

(Means for Solving the Problems) Thus, according to the present invention, in a plastisol composition containing a vinyl chloride resin for plastisol, a plastisol admixture resin, and a plasticizer, the admixture resin contains 30% vinyl halide by weight. % or more of polymer particles having an average particle diameter of more than 10 μm to 150 μm, a monomer containing 60% by weight or more of methyl methacrylate is added to the polymer particles 1.
00 parts by weight, 10 to 150 parts by weight of the plastisol composition is obtained by coating, polymerizing, and then drying.

The core polymer particles used in the present invention have an average particle diameter of more than 10μ to 150μ, particularly 30 to 60μ, which is suitable for mixing with plastisol, and the 1M turbidity polymerization method is used for their production. Good. Monomers used in the polymerization of the core particles include vinyl halides such as vinyl chloride and vinylidene chloride alone or together with fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl caproate, and vinyl laurate. , isobutyl vinyl ether, hexyl vinyl ether.

Vinyl ethers such as cetyl vinyl ether.

Vinyl halide resins such as acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; and methacrylic acid alkyl esters such as methyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. A mixture with a monomer that lowers the melting temperature is used, but other monomers may also be used in combination.

The composition of these monomers can be selected depending on the desired physical properties, but it is 30 to 100% by weight of vinyl halides, preferably 60% by weight or more, and 70 to 0% by weight of monomers that lower the melting temperature. , preferably 0.1 to 30% by weight.

In addition, as catalysts for 1 polymerization, diacyl peroxides such as dibenzoyl peroxide 5 diaa 5-)limethylhexanoyl peroxide, dilauroyl peroxide, diinopropylberoxydicarbonate, di5eC
- Peroxydicarbonates such as butyl peroxydicarbonate and di-2-ethylhexyl peroxydicarbonate.

t-j tylperoxypivalate% Peroxyesters such as t-butylperoxyneodecanoate, other organic peroxides such as acetylcyclohexylsulfonyl peroxide, disuccinic acid peroxide, azobis It can be selected from oil-soluble catalysts such as azo compounds such as imbutyronitrile, but water-soluble catalysts such as persulfates such as ammonium persulfate, potassium persulfate, and inorganic peroxides such as hydrogen peroxide may also be added. Also good.

Further, the suspending agent used in the present invention may be any known suspending agent, such as partially saponified polyvinyl alcohol, vinyl acetate-maleic anhydride copolymer.

Examples include styrene-maleic anhydride copolymer, polyvinylpyrrolidone, gelatin, starch, methyl cellulose, hydroxypropyl cellulose, and surfactants such as alkyl sulfate salts such as sodium lauryl sulfate and sodium myristyl sulfate. , sodium dodecylbenzenesulfonate,
alkylaryl sulfonates such as potassium dodecylbenzenesulfonate, sulfosuccinate ester salts such as sodium dioctyl sulfosuccinate, sodium dihexyl sulfosuccinate, ammonium laurate,
Anionic surfactants such as fatty acid salts such as potassium stearate, polyoxyethylene alkyl sulfate salts, and polyoxyethylene alkylaryl sulfate salts.

Sorbitan esters such as curbitan monooleate and polyoxyethylene sorbitan monostearate, and polyoxyethylene alkyl ethers.

Pholoxyethene alkylphenyl ethers.

Ordinary nonionic surfactants such as polyoxyethylene alkyl esters and the like may be used in combination.

Furthermore, polymerization aids such as higher fatty acids and higher alcohols, and other additives may also be used. Polymerization temperature 1 Polymerization operation 1 Conventional techniques can be applied to the polymerization apparatus.

If the monomer used in the polymerization of the core particles inhibits the subsequent coating polymerization, it is preferable to remove unreacted monomers before the coating polymerization.

Following the polymerization of the core particles, coating polymerization is generally carried out by emulsion polymerization or suspension polymerization. As a monomer for coating polymerization,
It is essential to use 60% by weight or more of methyl methacrylate. Outside of methyl methacrylate, methyl acrylate, butyl acrylate.

Acrylic acid and acrylic esters such as 2-ethylhexyl acrylate, acrylic acid, methacrylic acid and methacrylic esters such as 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, and methacrylic acid, and others that can be copolymerized with methyl methacrylate. The monomer may be included in the coating monomer in an amount of 40% by weight or less. Suspending agents, surfactants, oil-soluble polymerization catalysts, water-soluble polymerization catalysts, polymerization aids, etc. used in coating polymerization may be selected from those mentioned above.

It is preferable to feed the monomer during coating polymerization intermittently or continuously during one polymerization. The polymerization temperature is generally in the range of 20 to 95°C, preferably 30 to 85°C.

The amount of monomer to be subjected to coating polymerization is 10 to 150 parts by weight, preferably 15 to 10 parts by weight, based on 100 parts by weight of the cut-out combined particles.
The range is 0 parts by weight. If it is less than 10 parts by weight, no coating polymerization effect will be observed, and if it exceeds 150 parts by weight, the properties of the electrified particles will not be exhibited, and this is not preferred from an economic point of view.

The slurry containing the polymer particles obtained through the above two-stage polymerization is dried by a conventional method to obtain a resin for plastisol admixture. Note that fluidized bed drying is industrially advantageous as a drying method.

By mixing the thus prepared resin with a conventional vinyl chloride resin for plastisol and a plasticizer, and if necessary, conventional compounding agents such as stabilizers, fillers, and diluents. A plastisol composition of the present invention that is homogeneous and has excellent viscosity properties is obtained.

The admixture resin in the present invention is generally 1 to 70% by weight based on the total amount of the vinyl chloride resin for plastisol, similar to ordinary vinyl chloride admixture resin.

It is preferably used in an amount of 10 to 50% by weight.

Examples of plasticizers include phthalate esters, adipate esters, phosphate esters, epoxyglycerides,
Common examples include citric acid ester type and polyester type. Reactive plasticizers can also be used.

Examples of the diluent include conventional diluents such as high-boiling aliphatic or aromatic hydrocarbons or ketone derivatives.

The amount of the compounding agent used may be within the same range as in ordinary plastisol compositions (for example, the plasticizer is 1 part vinyl chloride resin).
30-200 parts by weight per 00 parts by weight 1 usually 40-8
0 parts by weight), determined as appropriate depending on the application.

Apply the obtained plastisol at around room temperature according to the conventional method,
Formed into the desired shape by dipping, casting, etc., heating,
After being melted, it is cooled and solidified, making it more weather resistant than K.
Processed products with excellent flexibility etc. can be obtained.

(Effects of the Invention) The resin thus obtained by the method of the present invention has core particles with excellent toughness, flame retardancy, and flexibility, and weather resistance.

It is a two-layer structured particle consisting of a shell layer that has excellent fluidity and stability over time when made into a plastisol composition.

These rubbed particles provide a plastisol composition that is superior in both low-temperature processability and fluidity stability over time compared to conventional techniques.

In addition, when trying to obtain polymer particles other than two-layer particles by simultaneously polymerizing all the monomers, it is extremely undesirable as it causes a significant reaction delay and inhibits slurry stability, and it also leads to shell formation. When core particles are mixed with particles obtained by polymerizing the monomers used alone, the stability of fluidity over time is significantly inferior.

(Example) The present invention will be described in more detail with reference to Examples below. Parts and parts in the examples are based on weight unless otherwise specified.

The fluidity measurement of the plastisol composition was conducted using 45 parts of admixture resin, vinyl chloride resin for plastisol (Nippon Zeon Co., Ltd.
Zeo Co., Ltd./121) 55 parts, dioctyl phthalate 45
Stabilizer (AC-173 manufactured by Adeka Argus Co., Ltd.) 3
The plastisol obtained by mixing 1 part by Ishikawa method and degassing under reduced pressure was measured using a Brookfield viscometer (BM viscometer manufactured by Tokyo Keiki Co., Ltd.) using a positive 40-terp. The measurement was carried out at 25° C. at 6 revolutions/min.

In addition, the strength measurement of the molded sheet was carried out by applying the same composition as above on a 0.3 m thick aluminum plate at 0.5 ± 0.05 t.
The cast material was heat-formed at a predetermined temperature for 5 minutes, and the obtained sheet was used as a No. 3 dumbbell sample piece.

The breaking strength was measured using a TCM500 tensile tester manufactured by Shinko Tsushin Kogyo Co., Ltd.

Example 1 lO equipped with stirring blades! In a stainless steel autoclave,
6 kg of water in which 15 g of gelatin shown in Table 1 was dissolved was charged, and the pH was adjusted to 12 with ammonia.

Prepare t-butylperoxypyvalley) 1.2.9.

After degassing, 2.4 kg of vinyl chloride monomer and 0.6 kg of vinyl acetate monomer were charged, and suspension polymerization was started at 58°C.

Polymerization was carried out until a predetermined polymerization rate was reached. After recovering the unreacted monomers, a portion of the resulting polymer slurry was dehydrated and dried (Comparative Examples 1 and 20 Polymer Samples X The particle sizes of these were as shown in Table 1. Using the remaining polymer slurry, a series of resins were prepared with varying ratios of core particles/coating monomer.

That is, using the same autoclave, one reaction temperature was 60°C.
Add 0.5 parts of potassium persulfate per 100 parts of the coating monomer at the initial stage of polymerization, add 0.2 parts of sodium dodecylbenzenesulfonate aqueous solution (as pure content) per 100 parts of the coating monomer, and A method of continuously feeding each for 4 hours was used.

The reaction was completed at a conversion rate of 95%. A resin was obtained by drying the obtained slurry in a fluidized bed, and the resin was subjected to fluidity measurement and molded sheet strength measurement.

The results are shown in Table 1. When methyl methacrylate is not used during coating polymerization (Experiment No. 1), or when it is used but in a smaller amount than in the present invention (Experiment No. 2), the strength of the formed sheet during low-temperature molding is is relatively good, but the viscosity stability of plastisol is extremely poor. Moreover, when the amount of methyl methacrylate is larger than that in the present invention (Experiment No. 7), although the viscosity stability of the plastisol is excellent, it is not preferable in terms of strength of the formed sheet and economic efficiency.

On the other hand, the fifth invention example (experiment number 3-6) is excellent in both plastisol viscosity stability and molded sheet strength.

Example 2 Polymerization was carried out in the same manner as in Example 1, except that the composition of the coating monomer was changed, and the polymerization was evaluated. From the results in Table 2, methyl methacrylate is excellent as the main monomer for coating, and the ratio of monomers that can be copolymerized with methyl methacrylate is 4% or less among the monomers for coating polymerization. is clearly superior.

Example 3 Polymerization was carried out in the same manner as in Example 1, except that the core particle composition was changed, and the polymerization was evaluated.

From the results in Table 3, it is further understood that according to the present invention, the viscosity stability of plastisol can be improved without impairing the strength of the molded sheet.

Table 1 Note: Monomer abbreviations have the following meanings.

vC: Vinyl chloride VAC: Vinyl acetate MMA: Methyl methacrylate Note The monomer abbreviations have the following meanings.

BA: Butyl acrylate EHA: 2-ethylhexyl acrylate EA
: Ethyl acrylate

Claims (1)

[Claims] In a plastisol composition containing a vinyl chloride resin for plastisol, a plastisol admixture resin, and a plasticizer, the admixture resin has an average particle diameter of 10μ obtained by polymerizing a monomer containing 30% by weight or more of vinyl halide. Beyond 15
In the presence of polymer particles of up to 0μ, a monomer containing 60% by weight or more of methyl methacrylate is added to 100% of the polymer particles.
1. A plastisol composition obtained by coating and polymerizing 10 to 150 parts by weight and then drying.