JPH07109393A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To provide the composition providing molded products excellent in impact resistance also when processing conditions are different, by mixing and dispersing a powdery or cake-like PVC resin in a specific alkyl (meth) acrylate polymer latex. CONSTITUTION:(A) A powdery or cake-like PVC resin and (B) an alkyl (meth) acrylate polymer latex having a crosslinking degree of 30-95wt.% and containing >=80wt.% of an alkyl (meth)acrylate monomer giving a homopolymer having a Tg of <=-20 deg.C are mixed and dispersed each other to obtain the composition in which 2-30wt.%, preferably 5-20wt.%, of the alkyl (meth)acrylate polymer is adhered to the surfaces of 70-98wt.% of the PVC resin powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition having excellent impact resistance.

[0002]

2. Description of the Related Art Vinyl chloride resins are used in many applications as materials having excellent mechanical strength, weather resistance and chemical resistance. However, it has a drawback in impact resistance, and various improvement methods have been proposed.

As the above-mentioned improving method, there is generally a method of blending a rubber resin such as chlorinated polyethylene (CPE), acrylic rubber, methyl methacrylate-butadiene-styrene copolymer (MBS) as a reinforcing agent.

Regarding such a method, when a rubber type reinforcing agent such as CPE, acrylic type, MBS type is mixed with a vinyl chloride type resin, Japanese Patent Publication No. 50-37698,
Japanese Examined Patent Publication No. 52-1742, JP-A-64-36624
The publication discloses a method of mixing a granulated and dried rubber-based reinforcing agent with a dry vinyl chloride-based resin in a mixer.

However, this method has a drawback that it is difficult to uniformly disperse the particles of the rubber-based reinforcing agent during molding, and the impact resistance of the vinyl chloride resin varies depending on the processing conditions.

[0006]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a vinyl chloride resin composition having excellent impact resistance.

[0007]

As the vinyl chloride resin used in the present invention, for example, polyvinyl chloride; a copolymer of vinyl chloride monomer and a monomer copolymerizable with vinyl chloride monomer; vinyl chloride monomer And a graft copolymer of a vinyl chloride monomer and a graft copolymerizable resin; chlorinated polyvinyl chloride obtained by post-chlorinating polyvinyl chloride, and the like, and one or more of these can be used. .

Here, as the monomer copolymerizable with the vinyl chloride monomer, for example, ethylene, propylene,
Olefins such as butylene; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as isobutyl vinyl ether and phenyl ether; (meth) acrylic acid esters such as methyl acrylate, methyl methacrylate, ethyl methacrylate; vinylidene chloride, fluorine Examples thereof include vinyl halides such as vinyl chloride and the like, and one or more of these may be used.

Examples of the resin which can be graft-copolymerized with a vinyl chloride monomer include ethylene-vinyl acetate copolymers; ethylene-acrylic acid ester copolymers; chlorinated polyethylenes; polyurethanes. One kind or two or more kinds can be used.

The degree of polymerization of the above vinyl chloride resin is not particularly limited, but when it is small, the elongation at break and impact resistance of the molded product are lowered, and when it is large, the fluidity is deteriorated and molding becomes difficult. , 300 to 2000 are preferable,
More preferably, it is in the range of 400 to 1400.

As the method for polymerizing the vinyl chloride resin, any of emulsion polymerization, suspension polymerization, solution polymerization and the like can be used, but suspension polymerization is preferred.

A post-chlorinated vinyl chloride resin can also be used as the vinyl chloride resin. Post-chlorinated polyvinyl chloride is a post-chlorinated product of polyvinyl chloride, and the polyvinyl chloride used as a raw material is a homopolymer of vinyl chloride, a copolymer with vinyl chloride, a graft copolymer with vinyl chloride, etc. Any of the above may be used, and as the chlorination method, any of a gas phase chlorination method, a solution chlorination method, a suspension chlorination method and the like may be used.

For the purpose of the present invention, it is preferable to use a skinless vinyl chloride resin having no skin layer as the vinyl chloride resin. The effect obtained by using the skinless vinyl chloride resin is superior to the effect obtained by using the non-skinless vinyl chloride resin.

The alkyl (meth) acrylate polymer used in the present invention is composed of 80% by weight or more of an alkyl (meth) acrylate monomer whose homopolymer has a second-order transition point of -20 ° C or lower.

Examples of the alkyl (meth) acrylate monomer include ethyl acrylate, n-propyl acrylate, isobutyl acrylate, n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl methacrylate,
Examples thereof include n-decyl methacrylate, n-dodecyl methacrylate and 2-acryloyloxyethyl succinic acid, and one or more of these can be used.

The alkyl (meth) acrylate polymer may be copolymerized with another monomer copolymerizable with the alkyl (meth) acrylate monomer in an amount less than 20% by weight. As such a monomer,
In addition to alkyl (meth) acrylate monomers having a second-order transition point of a homopolymer higher than −20 ° C., for example, styrene-based monomers such as styrene and α-methylstyrene; acrylonitrile, and the like, and one or two of these may be mentioned. The above can be used.

Examples of the alkyl (meth) acrylate monomer having a homopolymer having a second-order transition point higher than -20 ° C. include, for example, methyl acrylate, isopropyl acrylate, t-butyl acrylate, n-tetradecyl acrylate and n-hexadecyl acrylate. , Lauryl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, n-hexyl methacrylate, n-tetradecyl methacrylate, n-butyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-acryloyl Examples thereof include oxyethyl phthalic acid, and one or more of these can be used. If the content of the above-mentioned other monomer increases, the impact resistance decreases, so the content is limited to 10% by weight or less.

If the cross-linking ratio of the above alkyl (meth) acrylate polymer is small, the impact resistance becomes insufficient, and if it is large, the workability is deteriorated and the surface smoothness is deteriorated. It is preferably 50 to 90% by weight. The cross-linking rate means 1 g of an alkyl (meth) acrylate polymer at 30 ° C in tetrahydrofuran (TH
F) It means the percentage of the insoluble portion when dissolved in 100 ml for 7 hours.

To crosslink the above alkyl (meth) acrylate polymer, there may be mentioned crosslinks using a polyfunctional monomer, melamine crosslinks, metal crosslinks, isocyanate crosslinks and the like, but crosslinks using a polyfunctional monomer are more preferable. Examples of the polyfunctional monomer in this case include ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol dimethacrylate, diallyl phthalate and diallyl malate.
One kind or two or more kinds can be used.

The method for obtaining the crosslinked alkyl (meth) acrylate polymer is not particularly limited, and examples thereof include emulsion polymerization method and suspension polymerization method. Considering it, the emulsion polymerization method is preferable.

During the polymerization of the alkyl (meth) acrylate polymer of the present invention, for example, a dispersion emulsifier, a polymerization initiator,
A pH adjuster, an antioxidant and the like can be used as appropriate.
Here, examples of the dispersion emulsifier include anionic surfactants, nonionic surfactants, partially saponified polyvinyl alcohols, cellulosic dispersants, gelatin, and the like, and examples of the polymerization initiator include potassium persulfate. Water-soluble polymerization initiators such as ammonium persulfate and hydrogen peroxide; organic peroxides such as benzoyl peroxide and lauroyl peroxide, and azo initiators such as azobisisobutyronitrile.

In the present invention, the vinyl chloride resin and the alkyl (meth) acrylate polymer are mixed and dispersed, but the vinyl chloride resin is mixed in the form of powder or cake to obtain the alkyl (meth) acrylate polymer. Are mixed in the state of a latex obtained by emulsion polymerization, suspension polymerization or the like. The solid concentration of the cake-shaped vinyl chloride resin is 50
It is preferably at least wt%. The solid content concentration of the alkyl (meth) acrylate polymer latex is preferably 20 to 50% by weight.

If the amount of the alkyl (meth) acrylate polymer attached to the surface of the vinyl chloride resin powder is small, the impact resistance is insufficient, and if it is too large, the mechanical strength, bending strength, tensile strength, etc. are reduced. 70-98% by weight of resin
On the other hand, it is limited to the range of 2 to 30% by weight, and more preferably 5 to 20% by weight. The method for mixing the vinyl chloride resin of the present invention and the alkyl (meth) acrylate polymer is not particularly limited, but, for example,
Examples include a spray mixing method, a hot blend mixer mixing method using a Henschel mixer, a super mixer, a cold blend mixer mixing method, an extrusion mixing method, and the like.

After the above-mentioned mixing, dehydration drying is carried out to obtain a vinyl chloride resin powder having an alkyl (meth) acrylate polymer adhered to the surface thereof, but quantitatively, forced drying is carried out without dehydration. The drying method is preferably a static drying method, a fluidized drying method, a gas stream drying method, a vacuum drying method, a vibration drying method, or the like.

If necessary, a heat stabilizer, a stabilizing aid, a lubricant, a processing aid, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a pigment and the like are added to the above resin composition. Good.

Examples of the heat stabilizer include organic materials such as dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin malate polymer and dibutyltin laurate. Tin stabilizers; lead-based stabilizers such as tribasic lead sulfate, dibasic lead phosphite, and lead stearate; calcium-zinc stabilizers; barium-zinc stabilizers; barium-cadmium stabilizers and the like. To be Examples of the stabilizing aid include epoxidized soybean oil and phosphoric acid ester.

Examples of the lubricant include paraffin wax, polyethylene wax, stearic acid, stearyl alcohol, butyl stearate and the like.
Examples of the processing aid include a weight average molecular weight of 100.
Less than 10,000 acrylic processing aids are included. Examples of the filler include calcium carbonate and talc. In addition, a small amount of a plasticizer such as di-2-ethylhexyl phthalate, dibutyl phthalate or di-2-ethylhexyl adipate may be added to the resin composition in order to improve the processability.

As a method of mixing the above resin composition,
Any method such as a method by hot blending or a method by cold blending may be used, and examples of the molding method include an extrusion molding method, an injection molding method, a calender molding method and a press molding method.

[0029]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, all% and parts in the following Examples and Comparative Examples are weight units.

Example 1 A latex of an alkyl (meth) acrylate polymer was produced as follows. In a reaction vessel equipped with a stirrer and a reflux condenser, 240 parts of distilled water, 1 part of higher alcohol sulfate ester salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hitenol N08),
After charging 0.1 part of ammonium persulfate, 100 parts of normal butyl acrylate monomer, and 10 parts of ethylene glycol dimethacrylate and replacing the inside of the container with nitrogen, the temperature of the reaction container was raised to 65 ° C. with stirring and heated for 5 hours. The reaction was completed by stirring. The solid content concentration at this time is 31
%Met. The cross-linking rate is 1 g of the alkyl (meth) acrylate polymer at 30 ° C. in tetrahydrofuran (THF) 1.
Immerse in 00 ml for 7 hours, determine the dry weight of the insoluble part,
(Dry weight of insoluble part (g)) / (sample 1g) × 100
Calculated from the formula The above latex as solid content 1
0 parts and 90 parts of vinyl chloride resin (powdered) are supplied to a super mixer and mixed, and then supplied to an oven.
A vinyl chloride resin composition was obtained by drying at 0 ° C. for 48 hours.

100 parts of this vinyl chloride resin composition, 3 parts of a tin stabilizer (ONZ-142F, manufactured by Sankyo Machine Gosei Co., Ltd.) and polyethylene wax (W by Hoechst Japan, W)
AX-OP) 0.5 part was mixed. 190 this mixture
After kneading with a roll kneader at ℃ for 3 minutes, press-mold at 195 ° C for 6 minutes at a pressure of 75 kg / cm ² and a thickness of 3 mm.
Got a plate of. The Izod impact value and the flexural modulus were determined using the above molded sample. The Izod impact test was performed at 23 ° C. on the notched sample according to JIS K7110. Flexural modulus is ASTM
It was determined from the results of tests conducted according to D 790.
Alkyl (meth) acrylate polymer monomer composition,
Table 1 shows the crosslinking rate, the addition amount, the type of vinyl chloride resin used, the above-mentioned physical properties, and the like.

Examples 2 to 12 Vinyl chloride resin compositions were obtained in the same manner as in Example 1 except that the monomer composition of the alkyl (meth) acrylate polymer was changed as shown in Table 1. A plate was obtained. The plate was then tested and the test results are shown in Table 1.

In Table 1, APS stands for ammonium persulfate and OPP stands for 2-ethylhexyl peroxydicarbonate. The vinyl chloride resin is TS-1000R (polymerization degree 1000) manufactured by Tokuyama Sekisui Industry Co., Ltd., and C
PVC is a chlorinated vinyl chloride resin (made by Tokuyama Sekisui Industry Co., Ltd.,
HA-34F: chlorine content 64%). Acrylic impact modifier is manufactured by Rohm & Haas Company, Paraloid KM-
It was 334.

[0034]

[Table 1]

Comparative Examples 1 to 4 A vinyl chloride resin composition was obtained in the same manner as in Example 1 except that the monomer composition of the alkyl (meth) acrylate polymer was changed as shown in Table 2. Got The plate was then tested and the test results are shown in Table 2. Abbreviations and the like of each item in Table 2 have the same meanings as in Table 1.

[0036]

[Table 2]

Examples 13 to 22 An alkyl (meth) acrylate polymer latex solution obtained by polymerizing a predetermined amount of an alkyl (meth) acrylate monomer shown in Table 3 was used as a cake-shaped vinyl chloride resin (water content 25 (Wt%) was mixed and dispersed in the proportions shown in Table 3 to obtain a vinyl chloride resin composition and obtain a plate in the same manner as in Example 1. The plate was then tested and the test results are shown in Table 3. The abbreviations of the items in Table 3 have the same meanings as in Table 1.

[0038]

[Table 3]

Examples 23 to 32, Comparative Examples 5 to 7 Alkyl (meth) acrylate monomers in the proportions shown in Tables 4 and 5 were polymerized, and these were applied to skinless and ordinary vinyl chloride resins. Example 1 was repeated, except that the mixing and dispersion ratios were changed, and that the roll kneading temperature and the press temperature when forming the plate were changed as shown in Tables 4 and 5. Test the plate obtained,
The test results are shown in Tables 4 and 5. Flexural modulus is 19
It is a measured value of a sample obtained by roll kneading at 0 ° C. In Tables 4 and 5, as the skinless vinyl chloride resin, VINICRON 2000M (polymerization degree 1000) manufactured by Mitsui Toatsu was used. The skinless CPVC used was a product of chlorination of Vinylon 2000M with a chlorine content of 64%. Other abbreviations and the like represent the same as those in Table 1.

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

The vinyl chloride resin composition of the present invention contains 80% by weight or more of an alkyl (meth) acrylate monomer on the surface of vinyl chloride resin powder and has a crosslinking ratio of 30 to 9
Since the alkyl (meth) acrylate polymer of 5% by weight is uniformly adhered, a molded article having excellent impact resistance can be stably obtained regardless of processing conditions.

Claims (1)

[Claims] 1. A powdery or cake-shaped vinyl chloride resin and 80% by weight or more of an alkyl (meth) acrylate monomer having a homopolymer having a second-order transition point of -20 ° C. or less and a crosslinking ratio of 30 to 30. 95% by weight of alkyl (meth)
Alkyl (meth) acrylate polymer 2 to 70% to 98% by weight of vinyl chloride resin powder obtained by mixing and dispersing an acrylate polymer latex.
A vinyl chloride resin composition, wherein 30% by weight is attached.