JP2001114971A - Additive for vinyl chloride resin composition and extrudate obtained by using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an additive which, when added to a vinyl chloride resin prepared by grafting vinyl chloride onto an acrylic copolymer prepared by copolymerizing specific monomers giving homopolymers different in glass transition point, gives a vinyl chloride resin composition greatly improved in long-term extrudability without worsening the melt viscosity, melting point, and extrusion rate during extrusion and without degrading the physical properties of the resultant extrudate and to provide an extrudate obtained by using the additive. SOLUTION: This additive comprises a colorant containing 5 wt.% or higher but lower than 50 wt.% vinyl chloride resin composition which is prepared by the graft polymerization of vinyl chloride onto an acrylic copolymer formed from a monomer giving a homopolymer having a glass transition point lower than -20 deg.C, a monomer giving a homopolymer having a glass transition point of 120 deg.C or higher, and a polyfunctional monomer and has an average degree of polymerization by the viscosity method of 500 or higher but lower than 2,000; or this additive comprises a colorant containing 1 wt.% or higher but lower than 50 wt.% acrylic polymer lubricant having a wt. average mol.wt. lay the GPC method of 10,000 or higher but lower than 500,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an additive for obtaining a vinyl chloride resin composition which can be extruded even if the required time is long, and a molded article extruded using the additive. .

[0002]

2. Description of the Related Art Usually, extrusion molding of a vinyl chloride resin composition involves adding a heat stabilizer, a lubricant, a coloring agent, a processing aid, and the like to the vinyl chloride resin as required, and the extrusion process takes a long time. Resistance to thermal decomposition and discoloration of resin during processing (
Long term formability).

However, when the compatibility between the colorant pigment, the inorganic additive and the like and the vinyl chloride resin is low, the vinyl chloride resin itself builds up on the mold surface after a long time of extrusion. In some cases, it may cause an up or plate out, causing poor appearance such as streaks.

In particular, in order to improve the impact resistance and obtain a vinyl chloride resin excellent in balance with other physical properties, an acrylic copolymer obtained by copolymerizing a specific monomer having a different glass transition temperature of a homopolymer is used. In the case of a vinyl chloride resin having a high tackiness, such as a vinyl chloride resin obtained by graft copolymerization of vinyl chloride, build-up is promoted by the tackiness and the appearance may be easily deteriorated. Various additives have been proposed for the purpose of improving.

[0005] As one of the additives, as a conventional technique for a pigment system, for example, as disclosed in JP-A-4-366152, a dispersant such as an acrylic-styrene copolymer system or a polyester resin system is disclosed. A composition having good lubricity and good color development stability has been found using the above, but the long-term moldability is not sufficiently satisfactory for the vinyl chloride resin. At present, no good additive has been found for such a vinyl chloride resin in long-term moldability.

Accordingly, the present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, have found that the glass transition temperature of an alkyl (meth) acrylate monomer having a glass transition temperature of less than -20 ° C. Is -20 ° C
A vinyl chloride resin composition obtained by graft copolymerizing vinyl chloride by suspension polymerization with an acrylic copolymer obtained by mixing an acrylic mixed monomer comprising the above monomers and a polyfunctional monomer In contrast, as a dispersant in the colorant, the glass transition temperature of an alkyl (meth) acrylate monomer having a glass transition temperature of a homopolymer of less than −20 ° C. and the homopolymer is −20.
A vinyl chloride resin composition obtained by graft copolymerizing vinyl chloride by suspension polymerization to an acrylic copolymer obtained by mixing an acrylic mixed monomer comprising a monomer having a temperature of not less than ℃ and a polyfunctional monomer. object,
Alternatively, a weight average molecular weight of 10,000 to 50 by GPC method
By using 10,000 acrylic polymer lubricants as additives, the melt viscosity and melting temperature of the vinyl chloride resin at the time of extrusion molding, the extrusion speed do not deteriorate, and the physical properties of the extruded molded product do not decrease And that the long-term moldability was significantly improved, and the present invention was achieved.

[0007]

That is, an object of the present invention is to provide a vinyl chloride resin composition which does not deteriorate the melt viscosity, melting temperature and extrusion speed of the vinyl chloride resin during extrusion molding. The present invention also provides an additive whose long-term moldability is greatly improved without deteriorating the physical properties of the extruded molded article, and an extruded article using the same.

[0008]

Means for Solving the Problems The additive (invention 1) for a vinyl chloride resin composition according to claim 1 of the present invention contains a homopolymer having a glass transition temperature of less than -20 ° C in a coloring agent. A vinyl chloride monomer obtained by graft copolymerizing a vinyl chloride monomer onto an acrylic copolymer composed of an acrylic monomer, a monomer having a glass transition temperature of a homopolymer of −20 ° C. or higher, and a polyfunctional monomer. An additive for a vinyl chloride-based resin composition, wherein the resin composition is contained in an amount of 5 parts by weight or more and less than 50 parts by weight.

The additive (invention 2) for a vinyl chloride resin composition according to claim 2 of the present invention contains an acrylic resin having a weight average molecular weight of 10,000 or more and less than 500,000 by a GPC method in a coloring agent. An additive for a vinyl chloride resin composition, wherein the molecular lubricant is contained in an amount of 1 part by weight or more and less than 50 parts by weight.

An extruded product according to claim 3 of the present invention (invention 3) is an acrylic monomer having a glass transition temperature of a homopolymer of less than -20 ° C and a monomer having a glass transition temperature of a homopolymer of -20 ° C or more. And 100 parts by weight of a vinyl chloride resin composition obtained by graft copolymerizing a vinyl chloride monomer with an acrylic copolymer composed of a polyfunctional monomer and the vinyl chloride resin composition of Invention 1 or / and 2. An extruded product characterized by being mixed with 0.01 to less than 2 parts by weight of an additive for a resin composition and extruded.

The extruded product according to claim 4 of the present invention is
An extruded product according to Invention 3, wherein the extruded product is a tube.

Hereinafter, the present invention will be described in more detail. In the present invention, the mixing of the dispersant in the colorant is preferably performed by mixing the dispersant in advance to improve the dispersibility of the colorant, whereby a more sufficient mixed state is obtained and a uniform vinyl chloride resin composition is obtained. Because it becomes a thing.

In the first invention, the acrylic copolymer used to obtain a vinyl chloride resin composition having high impact resistance and excellent balance with other physical properties has a glass transition temperature of a homopolymer of -20. It is an acrylic copolymer composed of a monomer having a glass transition temperature of −20 ° C. or higher and an acrylic monomer having a glass transition temperature of −20 ° C. or lower and a polyfunctional monomer.

The alkyl (meth) acrylate monomer having a glass transition temperature of less than -20 ° C. is not particularly limited. Examples thereof include ethyl acrylate, n-propyl acrylate, isobutyl acrylate, n-butyl acrylate, sec-butyl acrylate, and n-butyl acrylate. Hexyl acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, isooctyl acrylate, n-decyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl acrylate, lauryl (meth) acrylate, 2-acryloyloxy Ethyl succinic acid and the like can be mentioned. These may be used alone or in combination of two or more.

The glass transition temperature of the homopolymer is -20 ° C.
The above monomer is not particularly limited, for example,
Methyl (meth) acrylate, ethyl methacrylate,
n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl acrylate, myristyl (meth) acrylate, palmityl (meth) Alkyl (meth) acrylates such as acrylate and stearyl (meth) acrylate; polar group-containing vinyl monomers such as 2-hydroxyethyl (meth) acrylate and 2-acryloyloxyethyl phthalic acid; styrene, α-methylstyrene, vinyltoluene and the like Aromatic vinyl monomers; unsaturated nitriles such as acrylonitrile and methacrylonitrile; and vinyl esters such as vinyl acetate and vinyl propionate. . These may be used alone or in combination of two or more.

The polyfunctional monomer is not particularly restricted but includes, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,6
-Di (meth) such as hexanediol di (meth) acrylate and trimethylolpropane di (meth) acrylate
Acrylate; tri (meth) acrylate such as trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate; pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa Diallyl compounds and triallyl compounds such as (meth) acrylate, diallyl phthalate, diallyl malate, diallyl fumarate, diallyl succinate and triallyl isocyanurate;
And divinyl compounds such as divinylbenzene and butadiene. These may be used alone or in combination of two or more.

The method for obtaining the above acrylic copolymer is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method. Considering the impact resistance, the emulsion polymerization method is preferred.

In the additive of the invention 1, a vinyl chloride resin obtained by graft-copolymerizing vinyl chloride with the above acrylic copolymer is used. The method for obtaining the vinyl chloride resin is not particularly limited, for example, an emulsion polymerization method,
Although a suspension polymerization method and the like are mentioned, a suspension polymerization method is preferably used.

Since the vinyl chloride resin produced by this production method is obtained by graft copolymerizing vinyl chloride with an acrylic copolymer, it is necessary to mold a vinyl chloride resin molded article having excellent impact resistance. Can be.

The degree of polymerization of the vinyl chloride resin is preferably 500 or more and 2000 or less as an average degree of polymerization by a GPC method in order to act as a dispersant. If the average degree of polymerization is less than 500, the long-term moldability deteriorates, which is not preferable. If it is more than 2,000, the compatibility with the base resin decreases, and the long-term moldability deteriorates.

As the pigment component of the colorant, known pigments conventionally used for thermoplastic resins can be used, and may be added according to a desired color. For example, organic pigments such as azo, benzimidazolone, diallylide, quinacridone, isoindolinone, bat, phthalocyanine, and dioxane; titanium oxide, carbon black, ultramarine, cobalt blue, red iron oxide, titanium yellow And inorganic pigments such as graphite.

The mixing ratio of the vinyl chloride resin composition resin as a dispersant is preferably 5% by weight or more and 50% by weight. If the mixing ratio is outside this range, the effect on long-term moldability is reduced. Not preferred.

The method for producing the coloring agent may be a conventionally known method, for example, a master batch type, a dry blend type, a paste type, a wet color type and the like. Among them, a dry blend type production method is particularly preferable in view of the dispersibility of the colorant. This production
A flake or powder is prepared by mixing a pigment and a dispersant with a Henschel mixer.

In the invention 2, the acrylic polymer lubricant used by mixing as a dispersant in the colorant is used for the purpose of improving long-term running properties, and its grade is not particularly limited. When the average molecular weight is 10,000 or more and less than 500,000, the long-term moldability is significantly improved without lowering the physical properties of the molded product and the processability during extrusion molding. If it is less than 10,000, there is no effect of improving long-term running properties, and if it is 500,000 or more, the effect as a lubricant is reduced and the effect as a dispersant is lost.

Examples of the acrylic polymer lubricant used as the dispersant include, for example, an acrylic polymer having a portion having excellent compatibility with a vinyl chloride resin containing methyl methacrylate as a main component and exhibiting lubricity. A multi-staged polymer or the like may be used.

The mixing ratio of the acrylic polymer lubricant in the colorant is preferably 1% by weight or more and less than 50% by weight, and if it is outside this range, the effect on long-term moldability is unfavorably reduced. . Further, a vinyl chloride resin may be added as a dispersant in addition to the acrylic polymer lubricant.

As the pigment component of the colorant, known pigments conventionally used for thermoplastic resins can be used, and may be added according to a desired color. For example, organic pigments such as azo, benzimidazolone, diallylide, quinacridone, isoindolinone, bat, phthalocyanine, and dioxane; titanium oxide, carbon black, ultramarine, cobalt blue, red iron oxide, titanium yellow And inorganic pigments such as graphite.

The method for producing the coloring agent may be a conventionally known method, and examples thereof include a master batch type, a dry blend type, a paste type, and a wet color type. Among them, a dry blend type production method is particularly preferable in view of the dispersibility of the colorant. This production
A flake or powder is prepared by mixing a pigment and a dispersant with a Henschel mixer.

Inventions 3 and 4 relate to an acrylic copolymer comprising an acrylic monomer having a glass transition temperature of a homopolymer of less than -20 ° C, a monomer having a glass transition temperature of a homopolymer of -20 ° C or higher, and a polyfunctional monomer. 100 parts by weight of a vinyl chloride resin composition obtained by graft copolymerization of vinyl chloride to a polymer by suspension polymerization, and an additive for the vinyl chloride resin composition of the invention 1 or / and 2 of 0.01
An extruded body and a tube, wherein the mixture is extruded by mixing at least 2 parts by weight of the extruded product.

The amount of the colorant added is determined according to the invention 1 and the invention 2.
Is 0.01 to less than 2 parts by weight based on 100 parts by weight of the vinyl chloride resin. If the amount of the coloring agent is 2 parts by weight or more, poor appearance and adhesion of a pigment component to a mold or the like occur, which is not preferable. If the amount is less than 0.01 part by weight, a desired color cannot be obtained, which is not preferable.
From the viewpoints of cost, appearance, and mold adhesion, a more preferable range is from 0.1 part by weight to 0.6 part by weight.

The vinyl chloride resin composition to which the additive of the present invention is added may further contain, if necessary, di-2-ethylhexyl phthalate (DOP) and di-2-adipate.
Plasticizers such as ethylhexyl (DOA); heat stabilizers; lubricants such as polyethylene wax and ester wax, stearic acid, monoglyceride, montanic acid wax, calcium carbonate; fillers such as glass fiber and carbon fiber; Agents, flame retardants, processing aids, ultraviolet absorbers and the like may be added.

The above composition can be obtained by mixing the above-mentioned vinyl chloride resin, colorant, and other additives such as a stabilizer and a lubricant with a usual mixing device, for example, a Henschel mixer.

The extruded product of the present invention can be obtained by extruding the above-mentioned vinyl chloride resin composition using an ordinary extruder and a mold. Molding temperature is about 190-21
It can be molded at 0 ° C. The molding temperature is preferably in the above range. If the temperature is below 190 ° C., various physical properties (especially impact properties) of the obtained molded article are reduced. It is not preferable because it causes a problem.

The mold used for molding can be any shape such as a rod-shaped body, a tubular body, an irregular cross-section such as a rain gutter, a plate-shaped body, a sheet, a film, and the like. Is in the extrusion molding of a tubular body, which was difficult to mold with the conventional technology.

(Examples and Comparative Examples) The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Examples 1 to 7, Comparative Examples 1 to 8) An acrylic copolymer and a vinyl chloride resin (A) were obtained by the following procedure.

<Preparation of Acrylic Copolymer> A reaction vessel equipped with a stirrer and a reflux condenser was charged with 2400 parts by weight of pure water,
10 parts by weight of an emulsifying dispersant (HITENOL N-08, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), 1 part by weight of ammonium persulfate, 1000 parts by weight of n-butyl acrylate, 4 parts by weight of trimethylolpropane triacrylate, and oxygen in the container Was replaced with nitrogen, and the reaction vessel was heated to 65 ° C. under stirring conditions.
Then, the mixture was heated and stirred for 5 hours to obtain an acrylic copolymer having a solid content of 30% by weight.

<Preparation of Vinyl Chloride Resin (A)> Next, 1060 parts by weight of the acrylic copolymer, partially saponified polyvinyl alcohol (Kuraray Povar L-8, Kuraray Co., Ltd.) were placed in a reaction vessel equipped with a stirrer and jacket. 250 parts by weight of a 3% aqueous solution of hydroxypropyl methylcellulose (Metroze 60SH50, manufactured by Shin-Etsu Chemical Co., Ltd.), 125 parts by weight of t-butyl peroxy neodecanoate, α-cumyl peroxy neodeca One part by weight of noate and 3 parts by weight of CaCl _{2 were} charged all at once, then the air in the polymerization reactor was discharged by a vacuum pump, and 6200 parts by weight of vinyl chloride was further charged under stirring conditions.
By stirring for 0 minute, vinyl chloride was uniformly mixed, and polymerization was started at a polymerization temperature of 50 ° C. by controlling the jacket temperature.

After 6.2 hours from the polymerization, the completion of the reaction was confirmed by lowering the pressure in the reactor to 5.8 kg / cm 2, and the defoaming agent (Toray Silicon SH5510, manufactured by Toray Industries) was pressurized. The reaction was stopped after the addition. Thereafter, unreacted vinyl chloride was removed, and further dehydration drying was performed to obtain a vinyl chloride resin (A) (average degree of polymerization: 1300 (viscosity method), acrylic content: 6.0% by weight).

An organic tin-based stabilizer (trade name “SNT” manufactured by Sankyoki Gosei Co., Ltd.) was added to 100 parts by weight of the vinyl chloride resin (A).
-461K)), 1.0 part by weight, stearic acid 0.5 part by weight, ester lubricant (manufactured by Riken Vitamin Co., trade name "SG
22 ") 1.0 part by weight, a polyethylene-based lubricant (manufactured by Mitsui Chemicals, trade name" Hiwax220MP ") 1.0 part by weight, a dispersant (an acrylic polymer lubricant (" L-1000 "manufactured by Mitsubishi Rayon Co., Ltd.)) and 0.4 parts by weight of each colorant mixed with a vinyl chloride resin (“TS800E” manufactured by Tokuyama Sekisui Kogyo Co., Ltd.) is added, mixed with a Henschel mixer (manufactured by Mitsui Miike Seisakusho) at 110 ° C., and then cooled to 40 ° C. Thus, a vinyl chloride resin composition was obtained.

The obtained vinyl chloride resin composition was extruded using a plast extruder (Laboplast mill, manufactured by Toyo Seiki Co., Ltd.). For the mold, test pieces were obtained using a slit die (slit width 25 mm, thickness 2 mm) capable of promoting evaluation of long-term moldability.

In order to obtain a tube as a molded article, the vinyl chloride resin composition was extruded from a 50 mm-diameter biaxial anisotropic extruder (trade name "BT-5" manufactured by Plastic Engineering Laboratory Co., Ltd.).
0 "), and a tube having a diameter of 20 mm was obtained under the conditions of a constant extrusion rate and a resin temperature of 200 ° C.

The following evaluations were performed on the vinyl chloride resin molded articles obtained in the above Examples and Comparative Examples. 1. Evaluation of long-term formability (evaluation by test piece) The occurrence of defects such as burrs and stripes during running was visually confirmed. A mark that occurred several minutes after the start of running was rated as X, a mark that occurred 1-2 hours later was rated as △, and a mark that did not occur for 3 hours was rated as ○. 2. Evaluation of mold adhesion (evaluation by test piece) Immediately after extrusion for 3 hours, the mold was disassembled, and the amount of deposits on the mold surface was visually observed. If there is no mold deposit, ○
Those that slightly adhered to the easily adhering parts such as corners were marked with △, and those that had a large amount of deposits were marked with x. 3. Evaluation of falling weight impact (evaluation by pipe) The falling weight impact strength of the pipe was measured in accordance with JIS-K6742. The weight of the weight was 9 kg, and the condition of the sample was adjusted immediately after being left at a temperature of 0 ° C. and at −10 ° C. for about 2 hours. 4. Appearance evaluation (evaluation by pipe) The external appearance of the pipe obtained by the above-mentioned extrusion evaluation was visually observed, and a good one was evaluated as 、, and a poor one with defects such as spots and streaks was evaluated as ×.

Table 1 shows the results of the evaluation.

[0045]

[Table 1]

[0046]

The additive for a vinyl chloride resin composition of the present invention has the above-mentioned effects, and a vinyl chloride resin copolymerized with an acrylic resin or the like blended therewith can be used in ordinary molding. It can be molded by a machine, has little adhesion to a mold even after continuous molding for a long time, and shows excellent stability in long-term molding. The extruded product obtained by extrusion-molding the composition of the present invention has good appearance and excellent physical properties, and particularly has a practically important effect in a pipe.

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Claims (4)

[Claims] 1. A colorant comprising an acrylic monomer having a glass transition temperature of a homopolymer of less than -20 ° C., a monomer having a glass transition temperature of a homopolymer of -20 ° C. or more, and a polyfunctional monomer. A vinyl chloride resin composition obtained by graft copolymerizing a vinyl chloride monomer with an acrylic copolymer as described above, wherein the vinyl chloride resin composition contains 5 parts by weight or more and less than 50 parts by weight. Additives. 2. A vinyl chloride resin characterized in that the coloring agent contains 1 to 50 parts by weight of an acrylic polymer lubricant having a weight average molecular weight of 10,000 to less than 500,000. Additives for compositions. 3. The glass transition temperature of the homopolymer is -20.
It was obtained by graft copolymerizing a vinyl chloride monomer to an acrylic copolymer composed of an acrylic monomer having a glass transition temperature of −20 ° C. or higher and an acrylic monomer having a homopolymer having a glass transition temperature of −20 ° C. or higher. 100 parts by weight of the vinyl chloride resin composition and 0.01 to 2 parts by weight of the additive for the vinyl chloride resin composition according to claim 1 or / and 2.
An extruded product characterized by being mixed with less than part by weight and extruded. 4. The extruded product according to claim 3, wherein the extruded product is a tube.