JPH0797512A - Production of polyvinyl chloride-polyurethane elastomer - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic elastomer having excellent tensile strength, not causing bad dispersion of calcium carbonate. CONSTITUTION:In producing a composite material comprising a polyvinyl chloride-based resin, a polyurethane composed of a polymer polyol and an isocyanate compound containing three or more isocyanate groups and calcium carbonate, calcium carbonate is premixed with the polyvinyl chloride-based resin, then blended with the polymer polyol and the isocyanate compound and urethane-forming reaction is carried out while melting and blending under shear stress by heating to provide the production method of a polyvinyl chloride- polyurethane elastomer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a composite resin composition comprising polyurethane, polyvinyl chloride and calcium carbonate.

[0002]

2. Description of the Related Art Conventionally, benzoyl peroxide, dicumyl peroxide, and t have been known as methods for improving the load-bearing deformability of polyvinyl chloride resins, that is, the compression set.
-Chlorination with organic peroxides such as butyl peroxide, diamine compounds such as 1,4-tetramethylenediamine and 1,6-hexamethylenediamine, sulfur compounds such as sulfur, tetramethylthiuram disulfide and triazinedithiol Method for crosslinking vinyl resin, method by component crosslinking using reactive plasticizer such as diallyl phthalate, epoxy resin, and further, crosslinked vinyl chloride resin crosslinked in advance during polymerization or crosslinked NBR having good compatibility with vinyl chloride resin, crosslinking There are a method of blending polyurethane and the like with a vinyl chloride resin, a method of using a vinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked product with diisocyanate and the like.

In these methods, when the vinyl chloride resin is cross-linked, it is possible to easily obtain a composition having a good compression set. However, on the other hand, the problem is (1) coloring due to poor thermal stability. There are problems that it is easy to do, (2) odor remains due to the residue of the cross-linking agent, and (3) if the degree of cross-linking is increased, a large amount of plasticizer is required to obtain a predetermined hardness.

When a reactive plasticizer is used, it is often a radical reaction system, and therefore the same problem as described above occurs.

Then, crosslinked vinyl chloride resin or crosslinked NB
When R and the like are blended with vinyl chloride resin, (1) the physical properties such as tensile strength and elongation are remarkably deteriorated due to their dispersibility in vinyl chloride resin, and (2) a large amount for adjusting hardness. However, there are problems such as (3) poor moldability when added in a large amount, and (4) poor weather resistance and heat aging resistance due to the butadiene component in the crosslinked NBR.

Further, the method of forming a cross-linked product by using a vinyl chloride resin having a reactive group such as a hydroxyl group with diisocyanate or the like is inferior in reactivity, so that the improvement effect is small.

In recent years, attention has been paid to a composite of vinyl chloride resin and polyurethane, and various methods have been proposed. For example, a method of dissolving polyurethane in a vinyl chloride monomer (VCM) and polymerizing VCM to obtain a composite of a vinyl chloride resin and polyurethane, a method of producing a hydroxyl group-containing vinyl chloride resin by polymerizing VCM in the presence of a polyol, There are a method of obtaining by urethanization reaction, and a method of obtaining by reacting by impregnating vinyl chloride resin with polyol, isocyanate, catalyst and the like.

However, the composites of vinyl chloride resin and polyurethane obtained by these methods are inferior in rubber elasticity and are not suitable for applications requiring these properties. If a urethane crosslinked product is produced using triisocyanate in such a method for producing a composite, the processability will be poor.

[0009] Further, as a commonly used composite method of a vinyl chloride resin and polyurethane, there is a method of polymer-blending the vinyl chloride resin and a polyurethane elastomer having a high elasticity in a roll or Banbury mixer. Since the composite obtained by this method is inferior in compression set, improvement is desired.

On the other hand, in recent years, there has been an increasing demand for easy molding processability required for large-sized injection molding, precision injection molding, etc., especially a decrease in melt viscosity, and further rubber properties such as compression set and creep resistance. Materials having low compression set and low melt viscosity are desired.

Among them, a method has been found in which a vinyl chloride resin, a polyol, an isocyanate compound and, if necessary, a plasticizer are melt-mixed under heating with a shearing force to cause a urethane reaction to obtain a composite. The composite obtained by this method is a material having a low compression set and excellent moldability. Then, it is possible to add calcium carbonate to this composite material to make it a material with more excellent cost performance, but the calcium carbonate to be added causes poor dispersion, and there are problems such as a decrease in tensile strength and a decrease in elongation. there were.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a composite material comprising polyvinyl chloride resin, polyurethane and calcium carbonate, in which calcium carbonate does not cause poor dispersion.

[0013]

SUMMARY OF THE INVENTION The present inventors have completed the present invention as a result of earnestly studying a method for producing a composite material in view of the above-mentioned current situation.

That is, according to the present invention, in producing a composite material composed of a polyvinyl chloride resin, a polyurethane composed of a polymer polyol and an isocyanate compound having 3 or more isocyanate groups and a calcium carbonate, the calcium carbonate and the polyvinyl chloride resin are used. A method for producing a polyvinyl chloride-polyurethane elastomer, characterized in that after pre-mixing, a polymer polyol and an isocyanate compound are added, and a urethane reaction is carried out while heating, melting and mixing under a shearing force.

The details of the present invention will be described below.

The polyvinyl chloride resin used in the present invention is a vinyl chloride homopolymer resin, a chlorinated vinyl chloride resin,
A vinyl chloride copolymer resin (for example, vinyl acetate-vinyl chloride copolymer) obtained by random copolymerization or block copolymerization with one or more monomers among all monomers copolymerizable with vinyl chloride monomer. Polymers, ethylene-vinyl chloride copolymers, etc.), and the above resins are used alone or as a mixture of two or more kinds.

The polyol used in the present invention is one or two of polyols selected from polyester-based polyols, polyether-based polyols, polycarbonate-based polyols, castor oil-based polyols and saponified EVA (ethylene-vinyl acetate copolymer). More than one seed is used. The number of functional groups of the polyol is not particularly limited as long as it is 2 or more.

The amount of polyol added is vinyl chloride resin 1
20 parts by weight or more and 900 parts by weight or less are preferable with respect to 00 parts by weight. If it is less than 20 parts by weight, the rubber elasticity will not be improved, and if it exceeds 900 parts by weight, processing may not be possible.

The isocyanate compound having three or more isocyanate groups used in the present invention is, for example, 2,4-
And 2,6-tolylene diisocyanate, m- and p-
Phenylene diisocyanate, 1-chlorophenylene-
2,4-diisocyanate, 1,5-naphthalene diisocyanate, methylene bisphenylene 4,4'-diisocyanate, m- and p-xylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, 3 of diisocyanates such as isophorone diisocyanate and trimethylhexamethylene diisocyanate
A monomer, 1,6,11-undecane triisocyanate,
Examples thereof include triisocyanates such as lysine ester triisocyanate and 4-isocyanate methyl-1,8-octamethyldiisocyanate, and polyfunctional isocyanates such as polyphenylmethane polyisocyanate, and one or more of these may be used. It

It is also possible to use the above-mentioned diisocyanates in combination. However, in this case, the number of moles of isocyanate groups in the triisocyanate compound is preferably 0.25 or more with respect to the number of moles of isocyanate groups in all the isocyanate compounds, and if it is less than 0.25, sufficient performance may not be exhibited due to insufficient crosslinking density.

Further, the molar ratio of the isocyanate group in the above isocyanate compound to the hydroxyl group in the above polyol is 0.
It is preferably in the range of 3 to 1.3. If it is less than 0.3, sufficient performance may not be exhibited due to insufficient crosslinking density even if only triisocyanate is used as the isocyanate compound, and if it exceeds 1.3, processing may not be possible.

The calcium carbonate used in the present invention is not particularly limited. Generally, calcium carbonate added to polyvinyl chloride resin or rubber may be used. The amount of calcium carbonate added is not particularly limited, but if it exceeds 500 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin, the molding processability may be significantly deteriorated, so it is preferably 500 parts by weight or less.

According to our study, it has been found that when calcium carbonate is added after the urethane reaction between the polyol and the isocyanate compound occurs, the calcium carbonate aggregates, resulting in poor dispersion and the tensile properties and the like remarkably deteriorated. On the other hand, when calcium carbonate is added before the urethane reaction, not only the dispersion becomes good, but also a composite material having surprisingly improved mechanical properties such as tensile strength is obtained. Whether or not the urethane reaction is proceeding can be easily evaluated by, for example, IR (infrared spectrum) measurement of the isocyanate group. In the IR measurement, the absorption of the isocyanate group is 2270 cm ^{-1 to} 2280 cm ^-1
This absorption appears in the vicinity and disappears when a urethane reaction is formed.

The calcium carbonate may be added before the urethane reaction as described above, but for convenience of operation, it is mixed with the powdered polyvinyl chloride resin in advance and then added with the polymer polyol. It is preferable to add an isocyanate compound.

There is no restriction on the use of plasticizers in the present invention. The plasticizer that can be used in the present invention,
For example, di-n-butyl phthalate, di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisodecyl phthalate, diisooctyl phthalate, octyldecyl phthalate, butylbenzyl phthalate, di-phthalate di- Phthalic acid plasticizer such as 2-ethylhexyl, di-2-ethylhexyl adipate (DOA), di-n-decyl adipate, diisodecyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate and the like aliphatic ester Plasticizers, trioctyl trimellitate, tridecyl trimellitate, and other pyromellitic acid plasticizers, tributyl phosphate, tri-2-ethylhexyl phosphate, 2-ethylhexyl diphenyl phosphate, tricresyl phosphate, and other phosphate esters Epoxy such as plasticizer and epoxy soybean oil System plasticizer, a polyester-based polymeric plasticizer such as, one or more of these can be used.

Further, in the present invention, the urethane reaction is carried out while heating, melting and mixing the above-mentioned raw materials under a shearing force, but the manufacturing machine used at this time is not limited and may be any commonly used manufacturing machine. Can be used. 2 for this example
Examples thereof include a shaft extruder, a single screw extruder, a kneader, a Banbury mixer, and a roll, but some of these may be used in combination.

Further, in the present invention, a heat stabilizer represented by a metal salt or hydrotalcite, a stabilizer such as an ultraviolet absorber, a coloring agent such as titanium oxide or carbon black,
Matting agents typified by partially crosslinked PVC, processing aids typified by acrylic resins, hydrolysis inhibitors typified by carbodiimide, zinc borate, flame retardants typified by antimony trioxide, etc. It is possible to add, and it is also possible to add partially cross-linked NBR and thermoplastic polyurethane.

[0028]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Example 1 Ethylene-vinyl chloride copolymer obtained by suspension polymerization method in a Banbury mixer in a Henschel mixer having an internal volume of 10 liters (Leuron E-2800, Toso Co., Ltd.)
100 parts by weight, barium stearate 2 parts as a stabilizer, zinc stearate 1 part, as an amine scavenger Nissan Ferro Organic Chemical Co., Ltd. trade name BP-331, 1.5
Parts, and further 50 parts by weight of precipitated calcium carbonate whose surface was treated with fatty acid as calcium carbonate (manufactured by Shiraishi Industry Co., Ltd., trade name, white gloss CCR, average particle size 0.12 μm) were charged and stirred at a rotation speed of 950 rpm for 2 minutes. . Separately from this, a polymer polyol obtained by condensation polymerization of 1,4-butanediol, ethylene glycol and adipic acid (manufactured by Nippon Polyurethane Co., Ltd., trade name Nipporan 4
042, number average molecular weight 2000) 80 parts by weight and DOP
100 parts by weight of (di-2-ethylhexyl phthalate) was mixed, and hexamethylene diisocyanate trimer (product name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) was mixed therein.
13.4 parts by weight (NCO group / OH group ratio = 0.85) and 0.015 part of dibutyltin dilaurate as a catalyst were charged and mixed at room temperature.

Internal volume 1700 cc, casing temperature 15
The powder component mixed by the Henschel mixer was put into a Banbury mixer at 0 ° C. and stirred at a constant rotation speed. Separately, add liquid components mixed at room temperature,
Mix for 0 minutes.

After completion of the kneading, the obtained composite was put into a roll forming machine to form a sheet, which was then press-formed to have a thickness of 1 mm for a JISK6301 tensile test.
Further, this pressed product was used as a sample for the purpose of punching out into a dumbbell shape No. 3.

Example 2 A target composition was obtained by the same procedure as in Example 1 except that 100 parts by weight of precipitated calcium carbonate having a surface treated with fatty acid was used.

Example 3 A target composition was obtained by the same procedure as in Example 1 except that 150 parts by weight of precipitated calcium carbonate having a surface treated with fatty acid was used.

Example 4 The same procedure as in Example 1 was carried out except that heavy calcium carbonate (trade name, WHITON P-10, manufactured by Shiraishi Industry Co., Ltd., average particle size 0.4 μm) was used as the calcium carbonate. A composition was obtained.

Example 5 The target composition was obtained by the same procedure as in Example 4 except that 100 parts by weight of heavy calcium carbonate was used.

Example 6 The target composition was obtained by the same procedure as in Example 4 except that 150 parts by weight of ground calcium carbonate was used.

Example 7 Example 4 except that 25 parts by weight of ground calcium carbonate was used.
The target composition was obtained by the same operation as described above.

Comparative Example 1 A composite material was obtained in the same manner as in Example 1 except that calcium carbonate was not used.

Comparative Example 2 A composite material was obtained in the same manner as in Example 1 except that calcium carbonate was added after the urethane reaction. The completion of the urethane reaction was confirmed by taking out a sample from the Banbury mixer and observing the peak due to the isocyanate group by FT-IR (Fourier transform infrared spectroscopy). The kneading time after the addition of calcium carbonate was 10 minutes.

(Evaluation of Tensile Properties) JIS K6301
It was measured according to. The results are shown in Table 1.

[0041]

[Table 1]

[0042]

INDUSTRIAL APPLICABILITY As described above, the composite obtained according to the present invention becomes a thermoplastic elastomer having excellent tensile properties without causing defective dispersion of calcium carbonate.

Claims (1)

[Claims] 1. When producing a composite material composed of a polyvinyl chloride resin, a polyurethane composed of a polymer polyol and an isocyanate compound having 3 or more isocyanate groups, and a calcium carbonate, calcium carbonate and a polyvinyl chloride resin are previously prepared. A method for producing a polyvinyl chloride-polyurethane elastomer, which comprises mixing a polymer polyol and an isocyanate compound after mixing, and carrying out a urethane reaction while heating, melting and mixing under a shearing force.