JPH07188494A - Production of vinyl chloride polymer/polyurethane composite material - Google Patents

Abstract

PURPOSE:To obtain continuously a composite material comprising a polyurethane, PVC and a plasticizer. CONSTITUTION:This production process is one for continuously producing a vinyl chloride polymer/polyurethane composite material comprising melt-mixing a vinyl chloride polymer with a polymer polyol, an isocyanate compound having at least three isocyanate groups and a plasticizer under shear and heat with an extruder, which process comprising feeding the respective starting materials into a twin-screw extruder preferably of a self-cleaning type, effecting the urethanization reaction at 160 deg.C or below in this extruder and accomplishing the urethanization reaction at 100-160 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention continuously produces a PVC-PU composite comprising a polyurethane (hereinafter referred to as PU) excellent in compression set, a vinyl chloride polymer (hereinafter referred to as PVC) and a plasticizer. On how to do.

[0002]

2. Description of the Related Art PU is excellent in wear resistance, low temperature characteristics, oil resistance, gasoline resistance, etc. Furthermore, it is possible to obtain arbitrary physical properties from flexible to hard by combining constituent raw materials. , Used in various fields.

On the other hand, PVC is a thermoplastic resin having excellent workability and versatility, which is industrially used as pipes, corrugated sheets, sashes and films, sheets, leathers, wire coatings, hoses and sundries. Widely used in.

Conventionally, as a method for improving the load-bearing deformability of PVC, that is, the compression set, organic peroxides such as benzoyl peroxide, dicumyl peroxide, t-butyl peroxide, and 1,4-tetramethylene are used. Diamines, diamine compounds such as 1,6-hexamethylenediamine, sulfur, tetramethylthiuram disulfide,
P using a sulfur-based compound such as triazinedithiol
A method of cross-linking VC, a method of cross-linking components using a reactive plasticizer such as diallyl phthalate or epoxy resin, and further cross-linked PVC or P previously cross-linked during polymerization.
A method of blending a cross-linked nitrile butadiene rubber (hereinafter referred to as cross-linked NBR) having good compatibility with VC with PVC,
There is a method of using PVC having a reactive group such as a hydroxyl group to form a crosslinked product with diisocyanate or the like.

Among these methods, the method of crosslinking PVC makes it possible to easily obtain a composition having a good compression set, but on the other hand, the problem is that the crosslinking agent is poor in thermal stability and easily colored. There is a problem that the odor remains due to the residue.

Since the method using a reactive plasticizer is often a radical reaction system, the same problem as described above occurs.

The method of blending cross-linked PVC or cross-linked NBR with PVC is related to their dispersibility in PVC, and the physical properties such as tensile strength and elongation are remarkably deteriorated. In addition, there are problems such as poor heat aging resistance. Further, in the method of forming a crosslinked product by using diisocyanate or the like using PVC having a reactive group such as a hydroxyl group, the reactivity is inferior, so that the improvement effect is small.

In recent years, attention has been paid to composites of PVC and PU,
For example, the following method has been proposed.

(1) Blend of PVC and thermoplastic PU In order to obtain an inexpensive mixture having excellent physical properties, thermoplastic PU is used.
And PVC have been proposed and have been used in some fields. However, since thermoplastic PU is usually in the form of flakes or pellets of several mm,
When it is blended with VC powder, its workability is poor, and when additives such as stabilizers are mixed, it becomes non-uniform due to different particle sizes, and the mechanical strength of the molded product is insufficient and the appearance is poor. I have a problem. In addition, the thermoplastic P
There is also a method of powdering U and blending it with PVC powder,
It is often difficult to powder a relatively soft thermoplastic PU that meets the physical properties required for ordinary mixed resins. Furthermore, a thermoplastic PU suitable for the physical properties required for mixed resins
The melting temperatures of PVC and PVC are often different, which makes mixing difficult, resulting in poor workability.
In addition, there is a problem that blending the crosslinked PU results in poor mechanical strength.

(2) Graft polymer of PVC and thermoplastic PU Vinyl chloride monomer (hereinafter referred to as VCM) is disclosed in JP-A-58-40312, JP-A-58-42611, JP-A-58-37019 and the like. A grafting by suspension polymerization of a thermoplastic PU soluble in water and VCM is proposed and a composition is disclosed. Since these compositions require that thermoplastic PU be dissolved in VCM and uniformly mixed, the composition and blending amount of PU must be restricted. For example,
PU is thermoplastic and has a low softening point. Therefore, it is limited to a special type having almost no hard segment in the molecular chain or a non-crosslinked type.

(3) Generation of PU in PVC A method described in Japanese Patent Publication No. 59-39464 has been proposed. According to the example, PVC is impregnated with a polyol, and then diisocyanate is added thereto to form PU in solid PVC.
According to this, since no plasticizer for PVC is used, there is no concern about elution of the plasticizer.

However, the PVC obtained by this method
The composite of PU and PU is inferior in rubber elasticity and is not suitable for applications requiring these properties. Further, in this method, if a large amount of a urethane-forming reaction catalyst is used to improve the productivity, the PU-forming reaction proceeds before the polyol and the isocyanate are completely impregnated into PVC to form a clay-like semi-gel form. The problem arises that

Further, JP-A-61-250044 and JP-A-6-250044.
Publications such as 2-1715 propose a method for producing a composite material composed of PVC, PU and a plasticizer. In this case, it is characterized by suppressing migration of the plasticizer, abrasion resistance, cold resistance, and oil resistance. However, in this method, since three kinds of polyol, isocyanate and plasticizer are used as the liquid component, it is necessary to reduce the amount of any one kind for the convenience of impregnation into PVC. Therefore, problems such as poor rubber elasticity and high hardness occur, and it is difficult to obtain a material having low hardness and excellent compression set.

[0014]

DISCLOSURE OF THE INVENTION The present invention provides a process for continuously obtaining a PVC-PU composite comprising PU, PVC and a plasticizer, which is excellent in compression set.

[0015]

In view of the above-mentioned circumstances, the present inventors have continuously produced PVC-PU composites excellent in compression set when continuously producing PVC and PU composites. As a result of extensive studies on the manufacturing method, the present invention has been completed.

That is, in the present invention, a vinyl chloride polymer (1), a polymer polyol (2), a compound (3) having three or more isocyanate groups and a plasticizer (4) are subjected to shearing force under an shearing force using an extruder. In the method for continuously producing a vinyl chloride polymer-polyurethane composite by heating, melting and mixing, each of the starting materials is supplied to an extruder, and the urethanization reaction is performed by the extruder at a temperature of 160 ° C. or lower. A vinyl chloride polymer characterized in that the urethanization reaction is completed at a temperature of 100 ° C. or higher and 160 ° C. or lower.
A method for producing a polyurethane composite.

The present invention will be described in detail below.

The PVC (1) used in the present invention is a vinyl chloride-containing polymer, which is a vinyl chloride homopolymer, a chlorinated vinyl chloride polymer, or any monomer that can be copolymerized with a vinyl chloride monomer. Among them, vinyl chloride copolymers obtained by random copolymerization, graft copolymerization or block copolymerization with one or more kinds of monomers are mentioned, and one or more kinds of the above polymers are used. To be done.

Examples of the monomer copolymerizable with the vinyl chloride monomer include ethylene, propylene, butene, pentene-1, butadiene, styrene, α-methylstyrene,
Acrylonitrile, vinylidene chloride, vinylidene cyanide, alkyl vinyl ethers, carboxylic acid vinyl esters, aryl ethers, dialkyl maleic acids, fumaric acid esters, N-vinyl pyrrolidone, vinyl pyridine, vinyl silanes, acrylic acid alkyl esters, methacryl Examples thereof include acid alkyl esters.

The polymerization degree of PVC is 400 or more and 100 or more.
Those of 00 or less, preferably 600 or more and 5000 or less, and more preferably 800 or more and 3000 or less are suitably used.

Polymer polyol used in the present invention (2)
Is one having two or more hydroxyl groups, and includes polyester polyol, polyether polyol, polycarbonate polyol, vinyl-based polyol, diene-based polyol, castor oil-based polyol, silicone polyol,
Examples thereof include polyolefin polyols and copolymers thereof, and they may be used alone or in combination of two or more. The polymer polyol (2) having a molecular weight of 300 or more and 10000 or less, preferably 500 or more and 5000 or less is suitably used.

Among the above polymer polyols (2), the polyester polyol can be obtained, for example, by condensation polymerization of dicarboxylic acid and short chain polyol. At this time, as the dicarboxylic acid component, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, phthalic acid, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid, itaconic acid. And the like, and one kind or two or more kinds are used. On the other hand, the short-chain polyol component is an aliphatic, alicyclic, aromatic, substituted aliphatic or heterocyclic dihydroxy compound, trihydroxy compound, tetrahydroxy compound, etc., such as 1,2-ethanediol, 1,2 -Propanediol, 1,4-butanediol, butenediol, 3-methyl-1,5-pentanediol, 1,6-
Hexanediol, 1,10-decamethylenediol,
2,5-dimethyl-2,5-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, 2-methyl-1,8-octanediol, 1,9-nonanediol, bis (β-hydroxy) Ethoxy) benzene, p-xylenediol,
Dihydroxyethyl tetrahydrophthalate, trimethylolpropane, glycerin, 2-methylpropane-
1,2,3-triol and 1,2,6-hexanetriol may be mentioned, and one or more of them may be used.

As another method for obtaining a polyester polyol, β-propiolactone, bivalolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-
One or more lactone compounds such as caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, and trimethyl-ε-caprolactone, and one or more hydroxy compounds selected from the above short-chain polyol components. It is also possible to use a method of reacting with.

Examples of the polyether polyol include polytetramethylene glycol, polyethylene glycol, polypropylene glycol, polyoxypropylene glycol and the like, and one kind or two or more kinds are used.

As the polycarbonate polyol, one of hydroxy compounds selected from the above-mentioned short chain polyols is used.
One obtained by the transesterification method from one kind or two or more kinds and diallyl carbonate, dialkyl carbonate or ethylene carbonate is used. For example,
Poly (1,6-hexamethylene carbonate), poly (2,2′-bis (4-hydroxyhexyl) propane carbonate) and the like are industrially produced. As another method for obtaining a polycarbonate polyol, a so-called phosgene method (or a solvent method) can be used.

In addition, vinyl-based polyols such as acrylic polyols obtained by copolymerization of acrylic acid ester with an acrylic monomer having a hydroxy group such as β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate, poly (1, Polybutadiene polyols such as 4-butadiene) and poly (1,2-butadiene), castor oil-based polyols such as polypropylene glycol ricinolate, silicone polyols, polyolefin-based polyols and the like can also be used.

The isocyanate compound (3) having 3 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, methylenebisphenylene 4,4'-diisocyanate, m- and p-xylene diisocyanate,
Hexamethylene diisocyanate, lysine diisocyanate, 4,4′-methylenebiscyclohexyl diisocyanate, isophorone diisocyanate, trimer of diisocyanate such as trimethylhexamethylene diisocyanate, 1,6,11-undecane triisocyanate, lysine ester triisocyanate, 4-isocyanate Examples thereof include triisocyanates such as methyl-1,8-octamethyldiisocyanate and polyfunctional isocyanates such as polyphenylmethane polyisocyanate, and one or more of these are used. It is also possible to use the above diisocyanates together as the isocyanate compound (3). However, in this case, it is desirable to set the number of moles of isocyanate groups of triisocyanate to 0.25 or more with respect to the number of moles of isocyanate groups of all the isocyanate compounds used.
If it is less than the above range, sufficient performance may not be exhibited due to insufficient crosslink density.

The ratio of isocyanate / hydroxyl group in the polymer polyol (2) and the isocyanate compound (3) is preferably 0.3 to 1.3 when diol is used as the polymer polyol (2). 0.3
If it is less than 3, even if only triisocyanate is used as the isocyanate compound (3), sufficient performance may not be exhibited due to insufficient crosslink density, and if it exceeds 1.3, processing may be difficult.

The total amount of the polymer polyol (2) used in the present invention and the compound (3) having 3 or more isocyanate groups is 3 with respect to 100 parts by weight of PVC (1).
The amount is 0 to 900 parts by weight, preferably 30 to 500 parts by weight, and more preferably 30 to 300 parts by weight. If it is less than 30 parts by weight, the compression set will not be improved, and if it exceeds 900 parts by weight, processing may be difficult.

The plasticizer (4) used in the present invention
Examples thereof include di-n-butyl phthalate, di-2-ethylhexyl phthalate (hereinafter referred to as DOP), di-n-octyl phthalate, diisodecyl phthalate, diisooctyl phthalate, octyldecyl phthalate, butyl phthalate. Benzyl, phthalic acid plasticizers such as di-2-ethylhexyl isophthalate, di-2-ethylhexyl adipate, di-n-decyl adipate, diisodecyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate, etc. Pyromellitic acid plasticizers such as aliphatic ester plasticizers, trioctyl trimellitate and tridecyl trimellitate, tributyl phosphate, tri-2 phosphate
-Phosphate ester plasticizers such as ethylhexyl, 2-ethylhexyl diphenyl phosphate, tricresyl phosphate,
Epoxy-based plasticizers such as epoxy-based soybean oil, polyester-based polymer plasticizers, etc. may be mentioned.
At least 1 part by weight and not more than 900 parts by weight, preferably 10 parts by weight or more and 500 parts by weight or less, and more preferably 30 parts by weight or more and 300 parts by weight or less can be used per 100 parts by weight of PVC (1). To be done.

Further, in the production method of the present invention, a general urethanization reaction catalyst may be added to the above starting material and used. Examples of the catalyst include amine catalysts such as triethylamine, triethylenediamine and N-methylmorpholine, tin catalysts such as tetramethyltin, tetraoctyltin, dimethyldioctyltin, triethyltin chloride, dibutyltin diacetate and dibutyltin dilaurate. Examples thereof include a catalyst and the like, and one or more of these can be used, and among these, dibutyltin dilaurate is preferably used. The amount of catalyst used depends on the activity of the catalyst used, but it is necessary for the urethanization reaction to proceed at a temperature of 160 ° C or lower in the extruder and to complete the urethanization reaction at a temperature of 100 ° C or higher and 160 ° C or lower. It is a large amount. Taking dibutyltin dilaurate as an example, an amount of 10,000 ppm or less is preferably used with respect to the total amount of the vinyl chloride polymer, the polymer polyol, the compound having 3 or more isocyanate groups, and the plasticizer.

The PVC-PU composite according to the present invention contains a stabilizer, a lubricant, a coloring agent, an inorganic filler represented by calcium carbonate, talc, etc., which is usually added to PVC to the extent that the performance thereof is not extremely deteriorated. A flame retardant typified by antimony trioxide or zinc borate may be added if necessary.

The extruder used in the present invention is not particularly limited as long as it is known, and examples thereof include a single-screw extruder, a twin-screw extruder and a multi-screw extruder. Of these, a self-cleaning twin-screw extruder is preferably used. If a self-cleaning twin-screw extruder is used, PU will not be accumulated around the screw and accumulated, and the extruder will not be inoperable. The direction of rotation of the extruder may be different or the same, but the same direction is preferable. L / D of extruder (L is screw length, D is screw diameter)
Is preferably 20 or more and 100 or less. Further, the extruder can be provided with a vent hole if necessary, and a screw having a kneading element can be used if necessary. The residence time of the above-mentioned raw material in the extruder is 0.3 minutes to 30 minutes, preferably 0.5 minutes to 10 minutes.
It is less than a minute.

The temperature conditions for heat-melt mixing under shearing force using an extruder are as follows: the urethanization reaction proceeds at a temperature of 160 ° C. or lower and the urethanization reaction at a temperature of 100 ° C. or higher and 160 ° C. or lower. Set to complete. 160
If the urethanization reaction is allowed to proceed and complete at a temperature in excess of ° C, the effect of improving compression set will not be sufficient. Also, 10
If the urethanization reaction is completed at less than 0 ° C., it is difficult to melt the PVC, and a strand-shaped product cannot be obtained and pellets cannot be formed.

The progress and completion of the urethanization reaction can be determined as the isocyanate consumption rate from the absorption of isocyanate with an infrared spectrophotometer.

In the present invention, PVC (1), polymer polyol (2), isocyanate compound (3) and plasticizer (4) are used as a method of supplying each starting material to the extruder.
May be uniformly mixed in a predetermined amount and supplied to the supply port, or PV may be obtained by uniformly mixing the polymer polyol (2), the isocyanate compound (3) and the plasticizer (4) as a liquid in a predetermined amount.
C (1) may be separately supplied into a plurality of groups, such as separately supplied to the supply port of the extruder. It is also possible to separately supply each starting material directly to the extruder through a plurality of supply ports, or to supply the starting materials separately in a plurality of groups.

When a catalyst is used, it may be supplied to the extruder alone, but it is preferable to supply it in a state of being uniformly dispersed in a liquid polymer polyol and / or an isocyanate compound and / or a plasticizer. .

[0038]

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

In all the examples, as the extruder, a co-rotating complete meshing twin-screw extruder having self-cleaning property (TEX30 (D = 30 mm, L /
D = 42)) was used. This extruder comprises 12 barrels and a die, and the barrels are C1 to C12 from the gearbox side toward the die side. C1 was equipped with a supply port and was water cooled. In addition, the barrel and die other than C1 can be temperature controlled independently.
C4, C5, C7, C9 and C11 each had a vent hole and were normally used with a lid, but the lid was removed as needed and sampling was performed to confirm the progress and completion of the urethanization reaction.

36% of screw length in all cases
Was carried out under the conditions of a screw rotation speed of 30 rpm using a screw having a kneading element that occupies The discharge rate is 3
It was set to Kg / h.

Isocyanate consumption was measured using a Fourier transform infrared spectrophotometer. The device is Nicole FT-I
R5DX Spectratech, Scan 100 times,
The measurement range was 80 μm × 80 μm, the detector was MCT, the measurement method was the transmission method, and the sample holding plate was barium fluoride. The sample sampled from the twin-screw extruder was put into liquid nitrogen to stop the progress of the reaction and stored. The infrared absorption spectrum of the stored sample was measured to observe the absorption of 2277 (cm ⁻¹ ) which is the characteristic absorption of the isocyanate group. At this time, the peak derived from the benzene ring of the plasticizer (DOP) as the reference peak 1
The absorption at 600 (cm ^-1 ) was also observed at the same time. The peak intensity at 2277 (cm ^-1 ) before the start of the reaction was 1600 (c
The value obtained by dividing the value obtained by dividing the peak intensity of m ⁻¹ ) was 0% as the isocyanate consumption rate, and the value obtained for the sampled sample was standardized to obtain the isocyanate consumption rate.

Example 1 Ethylene-vinyl chloride copolymer obtained by suspension polymerization method (Ryuron E-2800, manufactured by Tosoh Corporation) 100
Parts by weight, 2 parts by weight of barium stearate as a stabilizer,
1 part by weight of zinc stearate, 80.0 parts by weight of polymer polyol (manufactured by Nippon Polyurethane Co., Ltd., trade name: Nipolan 4067, number average molecular weight 2000), 100 parts by weight of DOP (di-2-ethylhexyl phthalate), hexamethylene Diisocyanate trimer (trade name Coronate HX manufactured by Nippon Polyurethane Co., Ltd.) 13.4 parts by weight (isocyanate / OH ratio = 0.85) and 0.088 parts by weight of dibutyltin dilaurate as a catalyst are mixed for 1 minute. Was prepared and supplied from the supply port of the twin-screw extruder. The temperature condition of the extruder was 110 ° C. from C2 to C12 and the die was 110 ° C.

When the extrudate was sampled and the isocyanate consumption rate was calculated to be 100%, the urethanization reaction was complete.

The extrudate was put into a sheet by a roll forming machine at 170 ° C., and a test piece was press-molded for compression set (JISK6301) test. The compression set was 36%.

Example 2 An extrudate was obtained in the same manner as in Example 1 except that the temperature conditions of the extruder were changed from C2 to C12 to 120 ° C and the die was 120 ° C. When the extruded product was sampled and the isocyanate consumption rate was determined to be 100%, the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 38%.

Example 3 An extrudate was obtained in the same manner as in Example 1 except that the temperature conditions of the extruder were changed from C2 to C12 to 130 ° C and the die to 130 ° C. When the extruded product was sampled and the isocyanate consumption rate was determined to be 100%, the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 39%.

Example 4 An extrudate was obtained in the same manner as in Example 1 except that the temperature conditions of the extruder were changed from C2 to C12 to 150 ° C and the die to 150 ° C. When the extruded product was sampled and the isocyanate consumption rate was determined to be 100%, the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 39%.

Example 5 The temperature conditions of the extruder were changed from C2 to C9 at 70 ° C. and C10.
Extrudates were obtained in the same manner as in Example 1 except that the temperature was changed from 130 to C12 at 130 ° C and the die was changed to 130 ° C. The extrudate was sampled and the isocyanate consumption rate was calculated to be 100
%, And the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 37%.

Comparative Example 1 An extrudate was obtained in the same manner as in Example 1 except that the temperature conditions of the extruder were changed from C to C12 at 170 ° C and the die at 170 ° C. When the extruded product was sampled and the isocyanate consumption rate was determined to be 100%, the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 42%.

Comparative Example 2 An extrudate was obtained in the same manner as in Example 1 except that the temperature conditions of the extruder were changed from C to C12 at 190 ° C and the die at 190 ° C. When the extruded product was sampled and the isocyanate consumption rate was determined to be 100%, the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 42%.

Comparative Example 3 Extruded from a twin-screw extruder in the same manner as in Example 1 except that the temperature conditions of the extruder were 90 ° C. from C2 to C12 and the die was 90 ° C. Not enough and clean strands.

Comparative Example 4 The temperature conditions of the extruder were changed from C2 to C3 at 110 ° C. and C4.
Extrudates were obtained in the same manner as in Example 1 except that the temperature was changed from 170 to C12 at 170 ° C and the die at 170 ° C. C4 and the extrudate were sampled and the isocyanate consumption rate was calculated to be 62% and 100%, respectively, and the urethanization reaction was completed.

When the compression set was measured in the same manner as in Example 1, it was 42%.

[0060]

According to the production method of the present invention, it becomes possible to continuously produce a PVC-PU composite having an excellent compression set.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between compression set and progress of urethanization reaction and completion temperature in Examples of the present invention.

Claims (2)

[Claims] 1. A vinyl chloride polymer (1), a polymer polyol (2), an isocyanate compound (3) having three or more isocyanate groups and a plasticizer (4) are heated under shearing force using an extruder. In the method for continuously producing a vinyl chloride polymer-polyurethane composite by melt-mixing, each of the starting materials is supplied to an extruder, and the urethanization reaction is allowed to proceed at a temperature of 160 ° C. or lower in the extruder. 1
A process for producing a vinyl chloride polymer-polyurethane composite, which comprises completing the urethanization reaction at a temperature of 00 ° C or higher and 160 ° C or lower. 2. The method for producing a vinyl chloride polymer-polyurethane composite according to claim 1, wherein the extruder is a self-cleaning twin-screw extruder.