JP2683257B2 - Vinyl chloride resin composition for agriculture - Google Patents

Description

TECHNICAL FIELD The present invention relates to an agricultural vinyl chloride resin composition, and more specifically, to a vinyl chloride resin containing a specific organic metal phosphate salt as a stabilizer, By adding a polymer with a specific molecular weight of methyl acid as the main monomer, plate-out (roll stain) during processing is extremely small, and coloring (thermal stability during processing) during processing is also reduced. The present invention relates to a vinyl chloride resin composition for agriculture, which is excellent and can withstand continuous processing for a long time.

[Prior art and its problems] Vinyl chloride resin is a general-purpose resin used in a wide range of applications, in particular, by taking advantage of features such as high strength and good transparency, an agricultural film, It is widely used as a seat.

However, vinyl chloride-based resin is poor in stability to heat and light, and has a drawback that it tends to undergo thermal decomposition mainly due to dehydrochlorination during heat molding processing, and when used for agricultural applications, Since it is used outdoors, it is known to undergo weathering deterioration such as hardening and browning under the influence of sunlight, dust, oxygen, and the like.

Conventionally, various heat stabilizers and weather resistance stabilizers have been used in order to improve heat stabilization and weather resistance of a vinyl chloride resin during heat molding.

As these heat stabilizers, carboxylic acid metal salts (metal soap), organic phosphoric acid metal salts, organic phosphite compounds, epoxy compounds and the like are known, and as the weather resistance stabilizer, various ultraviolet absorbers are known. , Hindered amine compounds and the like are known.

Among these heat stabilizers, organophosphoric acid metal salts are known to have a relatively large stabilizing effect. For example, JP-A-61-250045 discloses a zinc salt of organophosphoric acid and a specific organic phosphate. By using the phyto compound and the β-diketone compound in combination, the thermal stability and the weather resistance are excellent, and
It is described that a chlorine-containing resin composition for agricultural films having less bloom can be obtained.

As described in the above publication, the organic phosphoric acid metal salt is an excellent heat stabilizer, and since it has an effect of improving weather resistance, it is suitable as a stabilizer for agricultural vinyl chloride resins. However, there is a drawback that remarkable plate-out (roll stain) occurs during the heat-molding process and, further, coloring occurs after long-time processing. For this reason, in actual use, the processing must be frequently interrupted and the processing machine must be cleaned, which is not practically satisfactory.

For this reason, there has been a strong demand to find an additive that prevents roll fouling and suppresses coloring when an organic phosphoric acid metal salt is used.

[Means for solving the problem]

The inventors of the present invention have made extensive studies in view of the above-mentioned current situation, using methyl methacrylate as a main monomer, and by using a polymer having a specific molecular weight in combination, a conventional agricultural vinyl chloride resin composition It has been found that the biggest drawback is that the roll contamination is improved to a practical level.

The present invention has been made based on the above-mentioned findings. 100 parts by weight of a vinyl chloride resin, (a) 20 to 90 parts by weight of a plasticizer,
(B) 0.01 to 5 parts by weight of an organic phosphoric acid metal salt represented by the following general formula (I) or (II) and (b) a polymer having a molecular weight of 5,000 to 50,000 and 0.01 to 50,000 as a main monomer. 5
The present invention provides a vinyl chloride resin composition for agriculture, which is obtained by adding parts by weight.

(In the formula, R ₁ represents an alkyl group having 1 to 30 carbon atoms, an aryl group, an arylalkyl group or an alkylaryl group, and R ₂ represents a hydrogen atom or a group represented by R ₁ —O—.
M represents an alkaline earth metal or zinc atom. Hereinafter, the present invention will be described in detail.

In the compound represented by the general formula (I) or (II), examples of the alkyl group include methyl, ethyl, propyl, butyl, isobutyl, hexyl, octyl, 2-ethylhexyl, nonyl, denyl, dodecyl, myristyl, stearyl, Eicosyl, triacontyl, etc., and the aryl group or alkylaryl group includes phenyl, methylphenyl, ethylphenyl, cumenyl,
Butylphenyl, octylphenyl, nonylphenyl,
Examples thereof include dimethylphenyl and dinonylphenyl.

The alkaline earth metal represented by M includes calcium, magnesium, barium and strontium.

Therefore, the following compounds are typical examples of the organophosphate metal salt represented by the above general formula (I) or (II) of the component (b) used in the present invention.

The compounding amount of the above organophosphoric acid metal salt is a vinyl chloride resin 10
0.01-5 parts by weight, more preferably 0.05
３3 parts by weight.

Further, the polymer having a molecular weight of 5000 to 50000 as the main monomer of component (c), methyl methacrylate, used in the present invention, has methyl methacrylate as the main monomer and a small amount of acrylic acid; Alkyl acrylates such as methyl acrylate, butyl acrylate and octyl acrylate: Other alkyl methacrylates such as butyl methacrylate and octyl methacrylate; glycidyl methacrylate; acrylonitrile; vinyl chloride, butadiene; vinyl acetate; vinylidene chloride; itacone Acid; a copolymer with a copolymerization component selected from itaconic acid dibutyl ester and styrene, and 50% by weight of a polymer component from methyl methacrylate.
As mentioned above, those containing 70% by weight or more are preferable.

The polymer containing methyl methacrylate as the main monomer is
Usually, it is known as an impact resistance improver for hard vinyl chloride resins, and those having a molecular weight of 5,000 to 3,000,000 are used, and generally those having a molecular weight of 100,000 or more are widely used.

On the other hand, such an impact resistance improver is not usually used in an agricultural composition which is a soft vinyl chloride resin composition. Further, even if a polymer having a molecular weight of 100,000 or more is blended, the effect of improving the roll stain by using the organic phosphate metal salt is not recognized at all, and in the case where the organophosphate metal salt is not blended, the present invention is used. The effect of the present invention is considered to be an extremely unique effect observed only in the combination of the present invention, since the effect of improving the roll stain is not observed even if the polymer of the component (c) is blended.

Examples of the plasticizer as the component (a) used in the present invention include dibutyl phthalate, butyl benzyl phthalate, diheptyl phthalate, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, dilauryl phthalate, dicyclohexyl phthalate and dioctyl terephthalate; dioctyl. Adipate,
Adipate systems such as diisononyl adipate, diisodecyl adipate, di (butyldiglycol) adipate;
Triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, triethyl phosphate,
Tributyl phosphate, trioctyl phosphate,
Phosphates such as tri (butoxyethyl) phosphate and octyldiphenyl phosphate; other polyesters, tetrahydrophthalates, azelates,
Examples thereof include sebacate type, stearic acid type, citric acid type and trimellitate type. In particular, it is preferable to use a phthalate-based or phosphate-based plasticizer, and particularly when both are used in combination, a remarkable effect is recognized.

The amount of these plasticizers added is 20 to 9 per 100 parts by weight of the resin.
It is 0 part by weight, preferably 30 to 80 parts by weight. When the phthalate-based and phosphate-based plasticizers are used in combination, it is generally preferable to add 20 to 70 parts by weight of a phthalate-based plasticizer and 1 to 20 parts by weight of a phosphate-based plasticizer. .

Examples of the vinyl chloride resin to be the subject of the present invention include vinyl chloride homopolymers and copolymers of vinyl chloride and vinyl acetate, ethylene, and the like, and the vinyl chloride resin has a polymerization degree of about 500 to 3000. Usually commercially available resins can be used.

Further, the composition of the present invention can be used in combination with other stabilizers and other additives which are usually used in vinyl chloride resin compositions for agriculture.

Other stabilizers that can be used in combination with the composition of the present invention include carboxylic acid or phenolic metals (lithium, potassium, sodium, calcium, barium, magnesium, strontium, zinc, cadmium, tin, cesium, aluminum, organotin, etc. ) Salt, organotin mercaptide compound, inorganic metal compound, organic phosphite compound,
Examples thereof include epoxy compounds and pure organic stabilizing aids.

Examples of the carboxylic acid constituting the carboxylic acid or the metal salt of phenols include caproic acid, pelargonic acid, lauric acid, 2-ethylhexylic acid, myristic acid, palmitic acid, undecylenic acid, ricinoleic acid, linoleic acid, linoleic acid, neodecane. Acid, oleic acid, stearic acid, isostearic acid, 12-hydroxystearic acid, 12-ketostearic acid, chlorostearic acid, phenylstearic acid, arachidic acid, behenic acid, erucic acid,
Mixed fatty acids obtained from natural oils and fats such as aliphatic carboxylic acids such as brassic acid and tallow fatty acids, coconut oil fatty acids, soybean oil fatty acids and cottonseed oil fatty acids; benzoic acid, chlorobenzoic acid, toluic acid, salicylic acid, tert-butylbenzoic acid. ,
Aromatic carboxylic acids such as tertiary octyl salicylic acid; divalent carboxylic acids such as maleic acid and adipic acid, or their half-esters, and the like; examples of phenols include phenol, cresol, cyclohexylphenol, nonylphenol, dodecylphenol, and the like. To be

The addition amount of these metal salts is 0.01 with respect to 100 parts by weight of the resin.
-10 parts by weight, preferably 0.1-5 parts by weight.

Examples of the organic tin mercaptide compound include mono- or dimethyl tin, mono- or dibutyl tin, or mono- or dioctyl tin isooctyl thioglycolate or isooctyl mercaptopropionate.

The addition amount of these organotin mercaptide compounds is 10
0.01-5 parts by weight, preferably 0.05-3, relative to 0 parts by weight
Parts by weight.

Examples of the inorganic metal compound include oxides, hydroxides, carbonates, phosphates, pyrophosphates, double salt compounds of the above metals such as synthetic hydrotalcite, zeolites and the like.

The addition amount of these inorganic metal compounds is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the resin.

Examples of the organic phosphite compound include triphenyl phosphite and tris (2,4-ditert-butylphenyl)
Phosphite, tris (nonylphenyl) phosphite, tris (mono and dinonylphenyl) phosphite, diphenyldecylphosphite, trioctylphosphite, phenyldioctylphosphite, trioctylphosphite, diisodecylpentaerythritol diphosphite, di Stearyl pentaerythritol diphosphite, bis (2,4-ditertiary butylphenyl) pentaerythritol diphosphite, bis (2,6-ditertiary butyl-4-methylphenyl) pentaerythritol diphosphite, tetra (tridecyl ) Bisphenol A diphosphite, tetra (C _{12 to} C ₁₅ mixed alkyl) bisphenol A diphosphite, hexa (tridecyl)
-1,1,3-Tris (3-tert-butyl-4-hydroxy-
6-methylphenyl) butane triphosphite, diphenyl acid phosphite, bis (nonylphenyl) acid phosphite and the like can be mentioned.

The amount of these organic phosphite compounds added is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the resin.

Examples of the epoxy compound include bisphenol type and novolac type epoxy resins, epoxidized natural fats and oils such as epoxidized soybean oil and epoxidized linseed oil, epoxidized linseed oil fatty acid octyl and other epoxidized unsaturated fatty acid alkyl esters, and vinyl. Examples thereof include alicyclic epoxy compounds such as cyclohexene diepoxide.

The amount of these epoxy compounds added is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the resin.

Examples of the pure organic stabilizing aid include polyhydric alcohols such as pentaerythritol, dipentaerythritol, dipentaerythritol adipate, mannitol and sorbitol; β such as dibenzoylmethane, benzoylacetone, stearylbenzoylmethane and dehydroacetic acid. -Diketone compound; 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid didodecyl ester, 2
Examples include organic nitrogen-containing compounds such as phenylindole and melamine.

The amount of these pure organic stabilizing aids added is 0.001 to 5 parts by weight, preferably 0.005 to 3 parts by weight, based on 100 parts by weight of the resin.

These other stabilizers can be used in combination of two or more kinds according to the purpose. Generally, it is preferable to further use a combination of a metal salt of an organic acid / organic phosphite compound / epoxy compound in the composition of the present invention.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 [Compounding] Parts by weight Vinyl chloride resin (polymerization degree 1300) 100 Dioctyl phthalate 50 Tricresyl phosphate 5 Bisphenol A diglycidyl ether 2 Zinc stearate 0.6 Tetra (C _12-15 mixed alkyl) bisphenol A diphosphite 0.8 Methylenebis Stearic acid amide 0.5 Sorbitan monopalmitate 1.5 No.4 Barium salt 0.8 No.7 Zinc salt 0.2 No.12 Zinc salt 0.2 Sample compound 0.2 Using the above composition, 175 ° C, 10 rpm, roll gap 0.5 m
Roll processing was carried out under the condition of m, and the occurrence of stains on the roll was observed with time, and the coloring property at that time and the time until sticking to the roll were measured. Table 1 shows the results.

Example 2 [Compounding] Parts by weight Vinyl chloride resin (polymerization degree 1300) 100 Dioctyl phthalate 50 Tricresyl phosphate 5 Bisphenol A diglycidyl ether 3 Methylenebis stearamide 0.5 Calcium stearate 0.4 Zinc stearate 0.3 No.7 Zinc salt 0.3 No. 12 Zinc salt 0.3 Octyldiphenylphosphite 1 Dehydroacetic acid 0.1 Sample compound 0.2 Using the above formulation, the same test as in Example 1 was conducted. Table 2 shows the results.

Example 3 [Compounding] Parts by weight Vinyl chloride resin (polymerization degree 1300) 100 Dioctyl phthalate 45 Tricresyl phosphate 5 Bisphenol A diglycidyl ether 3 Methylenebis stearamide 0.5 Tetra (C _12-15 mixed alkyl) bisphenol A diphosphite 1 Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate 0.2 Zinc stearate 1 Dibenzoylmethane 0.04 Metabrene L-1000 0.2 Sample compound 0.5 Using the above formulation, as in Example 1. Was tested. Table 3 shows the results.

[Effects of the Invention] From the above results, it is clear that the vinyl chloride resin composition of the present invention has very little roll stain and remarkably little colorability during processing.

On the other hand, when the polymer of the present invention is not added or when a polymer other than the present invention is added, roll contamination is remarkable, and coloring during processing is also remarkable, which is unbearable for continuous processing for a long time. It is clear that Further, when the organophosphate metal salt of the present invention is not added, the effect is not recognized at all even if the polymer of the present invention is added, and the effect of the present invention is that the specific organophosphate metal salt and the specific methyl methacrylate are added. It is clear that the combination of the system polymers has a very specific effect.

Claims (1)

(57) [Claims] 1. A vinyl chloride resin of 100 parts by weight, (a) a plasticizer of 20 to 90 parts by weight, (b) the following general formula (I) or (II):
0.01 to 5 parts by weight of an organic phosphoric acid metal salt represented by and (c) a main monomer of methyl methacrylate, and a molecular weight of 5000 to 5000
A vinyl chloride resin composition for agriculture, which is obtained by adding 0.01 to 5 parts by weight of the polymer of 0. (In the formula, R ₁ represents an alkyl group having 1 to 30 carbon atoms, an aryl group, an arylalkyl group or an alkylaryl group, and R ₂ represents a hydrogen atom or a group represented by —O—R ₁ .
M represents an alkaline earth metal or zinc atom. )