JP3312403B2 - Method for producing polyvinyl chloride-polyurethane composite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite comprising a polyurethane (hereinafter referred to as PU) and a polyvinyl chloride-based polymer (hereinafter referred to as PVC) having excellent compression set and mechanical strength.

[0002]

2. Description of the Related Art PU is excellent in abrasion resistance, low-temperature characteristics, oil resistance, gasoline resistance, etc., and furthermore, it is possible to obtain any physical properties from soft to hard depending on the combination of constituent materials. , Used in various fields.

[0003] On the other hand, PVC is a commercially available thermoplastic resin having excellent workability, and is widely used as pipes, corrugated sheets, sashes and films, sheets, leathers, electric wire coatings, hoses and sundry goods. Widely used for

[0004] Conventionally, as a method for improving the load resistance of PVC, that is, the compression set, organic peroxides such as benzoyl peroxide, dicumyl peroxide, t-butyl peroxide, and 1,4-tetramethylene have been used. Diamines, diamine compounds such as 1,6-hexamethylenediamine, sulfur, tetramethyl turam disulfide,
PV with sulfur compounds such as triazinedithiol
A method of cross-linking C, a method of cross-linking components such as diallyl phthalate or epoxy resin, and a method of blending a cross-linked PVC preliminarily cross-linked at the time of polymerization or a cross-linked nitrile-butadiene rubber having good compatibility with PVC (hereinafter referred to as cross-linked NBR) with PVC. Having a reactive group such as a hydroxyl group
There is a method of using VC to form a crosslinked body with diisocyanate or the like.

In these methods, when crosslinking is performed on PVC, it is possible to easily obtain a composition having good compression set, but on the other hand, there is a problem in that the composition is inferior in heat stability and easily colored. There is a problem that an odor remains due to the residue of the agent.

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

[0007] When blending a crosslinked PVC or a crosslinked NBR with the PVC, the butadiene component in the crosslinked NBR significantly reduces the physical properties such as tensile strength and elongation due to their dispersibility in PVC. Problems such as poor heat resistance and heat aging resistance. Further, in the method of using a PVC having a reactive group such as a hydroxyl group to form a crosslinked product by diisocyanate or the like, the reactivity is poor, and thus the improvement effect is small.

In recent years, attention has been paid to the composite 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, a thermoplastic PU is used.
And PVC have been proposed and used in some fields. However, since thermoplastic PU is usually in the form of flakes or pellets of several mm, PV
When blending with C powder, its workability is poor, and when additives such as stabilizers are mixed, the particle size is not uniform, resulting in non-uniformity and poor mechanical strength and poor appearance of the molded product. There's a problem.

There is also a method of pulverizing thermoplastic PU and blending it with PVC powder. However, it is often difficult to pulverize a relatively soft thermoplastic PU which conforms to the physical properties required of a general mixed resin.

Furthermore, the melting temperatures of thermoplastic PU and PVC, which are suitable for the physical properties required of the mixed resin, are often different, which has the disadvantage that mixing becomes difficult and workability is poor.

There is also a problem that the mechanical strength is inferior when the crosslinked PU is blended.

(2) Graft polymer of PVC and thermoplastic PU JP-A-58-40312, 58-42611, 58
As described in JP-A-37019 and the like, grafting by suspension polymerization of a thermoplastic PU and VCM soluble in a vinyl chloride monomer (hereinafter referred to as VCM) has been proposed to provide a composition. . These compositions are thermoplastic P
Since it is necessary to dissolve U in VCM and mix homogeneously,
The composition and amount of PU must be restricted. For example, PU is a thermoplastic and has a low softening point. For this reason, it is limited to those of a special type that hardly contains a hard segment in the molecular chain or those that are not crosslinked.

(3) Production of PU in PVC A method as described in JP-B-59-39464 has been proposed. According to the example, the PVC is impregnated with a polyol, to which diisocyanate is then added to form PU in solid PVC. This is characterized in that there is no need to worry about elution of the plasticizer, because no plasticizer for PVC is used.

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.

[0016]

SUMMARY OF THE INVENTION The present invention provides compression set,
An object of the present invention is to provide a method for obtaining a composite composed of PU and PVC with high mechanical strength and high productivity without performing difficult pretreatment.

[0017]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present inventor, when producing a PVC / PU composite,
As a result of intensive studies on a method of obtaining a material having excellent compression set and mechanical strength, the present invention has been completed.

That is, according to the present invention, after the PVC is impregnated with the polymer polyol while stirring the PVC with a mixer,
Further, a compound having three or more isocyanate groups (tri-
Phenylmethane-4,4 ', 4 "-triisocyanate
With trimethylolpropane or hexanetriol
Multifunctionality obtained by reacting excess polyisocyanate
Excludes isocyanates. ) Impregnating a 該Po at that time
Having a rimer polyol and three or more isocyanate groups
The total amount of the compound is 30 parts by weight per 100 parts by weight of PVC.
The present invention relates to a method for producing a PVC-PU composite, wherein the amount is not less than 200 parts by weight and a crosslinked PU is produced in PVC.

Hereinafter, the present invention will be described in detail.

The PVC used in the present invention is a vinyl chloride-containing polymer, one of all monomers copolymerizable with a vinyl chloride homopolymer, a chlorinated vinyl chloride polymer, and a vinyl chloride monomer. Alternatively, a vinyl chloride copolymer obtained by random copolymerization, graft copolymerization or block copolymerization with two or more kinds, and the like, and one or more kinds of the above polymers are used.

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, vinyl carboxylate esters, aryl ethers, dialkyl maleates, fumarate esters, N-vinyl pyrrolidone, vinyl pyridine, vinyl silanes, alkyl acrylate esters, methacrylic acid Acid alkyl esters and the like.

The degree of polymerization of PVC is 400 or more and 100 or more.
Those having a molecular weight 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.

The polymer polyol used in the present invention is
It has two or more hydroxyl groups, polyester polyol, polyether polyol, polycarbonate polyol, vinyl polyol, diene polyol,
Castor oil-based polyols, silicone polyols, polyolefin-based polyols, and copolymers thereof, and the like, and one or more of these are used.

Polymer polyols having a molecular weight of 300 to 10,000, preferably 500 to 5,000 are suitably used.

The polyester polyol is obtained, for example, by subjecting a dicarboxylic acid and a short-chain polyol to condensation polymerization.

The dicarboxylic acid component includes 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. One or more of these acids are used.

The short-chain polyol component includes aliphatic, alicyclic, aromatic, substituted aliphatic or heterocyclic dihydroxy compounds, trihydroxy compounds, tetrahydroxy compounds and the like, for example, 1,2-ethanediol, , 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
-Hydroxyethoxy) benzene, p-xylenediol, dihydroxyethyltetrahydrophthalate, trimethylolpropane, glycerin, 2-methylpropane-1,2,3-triol and 1,2,6-hexanetriol. One or more are used.

As another method for obtaining a polyester polyol, β-propiolactone, bivalolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-
Caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, one or more lactone compounds such as trimethyl-ε-caprolactone, one or more hydroxy compounds selected from the above short-chain polyol components And a method of reacting the same.

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

As the polycarbonate polyol, one of the hydroxy compounds selected from the aforementioned short-chain polyols is used.
Those obtained by transesterification from a species or two or more species and diallyl carbonate, dialkyl carbonate or ethylene carbonate are 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 polycarbonate, 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 monomers having hydroxy groups such as β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate with acrylic acid esters, poly (1, Polybutadiene polyols such as 4-butadiene) and poly (1,2-butadiene), castor oil-based polyols such as polypropylene glycol ricinoleate, silicone polyols, and polyolefin-based polyols are used.

The compound having three or more isocyanate groups used in the present invention includes, for example, 2,4- or 2,6-tolylene diisocyanate, m- or p-phenylene diisocyanate, 1-chlorophenylene-2,4- Diisocyanate, 1,5-naphthalenediisocyanate, methylenebisphenylene 4,4'-diisoanate, m-
Or trimers of diisocyanates such as p-xylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, isophorone diisocyanate, and trimethylhexamethylene diisocyanate;
1-undecane triisocyanate, lysine ester triisocyanate, 4-isocyanatomethyl-1,8
Trifunctional isocyanates such as octamethyl diisocyanate or polyfunctional isocyanates such as polyphenylmethane polyisocyanate, and one or more of these are used. It is also possible to use the above diisocyanates in combination.

However, the number of moles of NCO groups of triisocyanate relative to the number of moles of NCO groups of all isocyanates is 0.1.
25 or more is desirable. If it is less than 0.25, sufficient performance may not be exhibited due to insufficient crosslinking density.

When the diol is used as the polyol, the NCO / OH ratio is preferably in the range of 0.3 to 1.3.
If it is less than 0.3, even if only triisocyanate is used as the isocyanate, sufficient performance may not be exhibited due to insufficient crosslinking density, and if it exceeds 1.3, processing may be difficult.

The total amount of the polymer polyol and the compound having three or more isocyanate groups used in the present invention is P
It is 30 parts by weight or more and 200 parts by weight or less , preferably 30 parts by weight or more and 150 parts by weight or less, more preferably 30 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of VC. If the amount is less than 30 parts by weight, the compression set of the composite may not be improved.
C may be difficult to impregnate.

The PVC-PU composite according to the present invention includes a stabilizer, a lubricant, a coloring agent, a catalyst for urethanization reaction such as dibutyltin dilaurate, calcium carbonate, calcium carbonate, and the like which are usually added to PVC to such an extent that the performance is not extremely reduced. Inorganic fillers such as talc and flame retardants such as antimony trioxide and zinc borate can be added as required.

In the present invention, a method of impregnating PVC with a polymer polyol and then impregnating a compound having three or more isocyanate groups is as follows. First, a mixer such as a ribbon blender with a jacket or a Henschel mixer (manufactured by Mitsui Miike Seisakusho) Then, the PVC powder is put into a high-speed mixer such as a super mixer (manufactured by Kawada Seisakusho), and a stabilizer for PVC is blended into the powder and mixed with stirring.
When a liquid stabilizer is used, it may be added to the polymer polyol in advance. While stirring the PVC blended with the stabilizer as described above with a high-speed mixer, the polymer polyol is added thereto, and the mixing is continued at 70 to 130 ° C., and the polymer polyol is impregnated into the PVC powder to form a fluid powder. A mixture is obtained. Further, a compound having three or more isocyanate groups is added to the mixture to obtain 70
When mixed at １３０130 ° C., the compound having three or more isocyanate groups is impregnated into the PVC powder, and the urethanization reaction starts in the PVC particles.

[0039]

The urethanization reaction can be completed by continuing the reaction at 70 to 130 ° C. in a high-speed mixer or by taking out the polymer polyol and a compound having three or more isocyanate groups at the stage when the impregnation is completed, and taking out and drying. The reaction is carried out at 60 to 120 ° C.

The PVC-PU composite thus obtained has not only good flowability and easy weighing with an automatic weighing machine or the like, but also good moldability with an extruder or an injection molding machine. .

[0042]

Hereinafter, the present invention will be described with reference to examples.
The present invention is not limited to these examples.

Example 1 A suspension polymerization method in a Henschel mixer having an internal volume of 10 liters
-Vinyl chloride copolymer obtained by
Ron E-2800, manufactured by Tosoh Corporation) 100 parts by weight, cheap
Charge 1 part by weight of calcium stearate as a stabilizer 9
The mixture was stirred at a rotation speed of 50 rpm for 2 minutes. Then,
Polymer polyol (Nippon Polyurethane)
Nipporan 4067, trade name, number average molecular weight
2000) 80.0 parts by weight are added and the temperature of the mixture is 110
The mixture was stirred and mixed for 10 minutes while maintaining the temperature at ° C. The mixture is
The result was a powdery mixture that could easily flow. Further this powder
Hexamethylene diisocyanate while stirring the mixture
Trimer (product name: Corone, manufactured by Nippon Polyurethane Co., Ltd.)
1E weight) (NCO / OH ratio = 0.8)
5), and maintain the temperature of the mixture at 110 ° C. while adding 1
The mixture was stirred and mixed for 0 minutes. The mixture is an easily flowable powder
A powdery mixture resulted. This powdery mixture is stirred at 110 ° C.
Stirring was continued to complete the urethanization reaction. Then
When the mixture is cooled to room temperature, the powdered PVC-PU composite
The body is obtained.

The PVC-PU composite obtained was rolled at 170 ° C. to form a sheet, and then subjected to compression set (J
Test specimens were press-molded for ISK6301) and tensile (JISK7113) tests, and compression set, tensile strength, and tensile elongation at break were measured. The results are shown below.

Compression set 39 % Tensile strength 250 Kg / cm ² Tensile elongation at break 250 % Further, tetrahydrofuran (hereinafter referred to as THF)
Say ) The insoluble content was measured and found to be 41 wt%.

The method for measuring the THF-insoluble content is as follows.

The composite is freeze-pulverized and accurately weighed (X
g). This is subjected to Soxhlet extraction by THF for 8 hours. The obtained extract is dried and the THF-soluble component in the extract is accurately weighed (Yg). The THF insoluble content is determined by the following equation. THF-insoluble matter (wt%) = 100 (XY) / X Comparative Example 1 A suspension polymerization method in a Henschel mixer having an internal volume of 10 liters
-Vinyl chloride copolymer obtained by
Ron E-2800, manufactured by Tosoh Corporation) 100 parts by weight, cheap
Charge 1 part by weight of calcium stearate as a stabilizer 9
The mixture was stirred at a rotation speed of 50 rpm for 2 minutes. What is this
Separately, polymer polyols (Nippon Polyurethane Co., Ltd.
Product name Nipporan 4067, number average molecular weight 2000)
8.7.4 parts by weight of hexamethylene diisocyanate
0 parts by weight (NCO / OH ratio = 0.85) for 1 minute
Was prepared. Add this to the Henschel mixer and mix
Stir and mix for 10 minutes while maintaining the temperature of the mixture at 110 ° C.
went. The mixture becomes a powdery mixture that can easily flow.
Was. This powdery mixture is further stirred and mixed at 110 ° C.
Thus, the urethanization reaction was completed. Then place the mixture in the chamber
Upon cooling to temperature, a powdered PVC-PU composite is obtained.
Was. The compression set of the obtained PVC-PU composite was measured.
The result was 52%.

The THF insoluble content of this composite was measured and found to be 0.1% by weight or less.

[0049]

[0050]

[0051]

Comparative Example 2 In Example 1 , 87.4 parts by weight of a polymer polyol (Nipporan 4067, trade name, manufactured by Nippon Polyurethane Co., Ltd., number average molecular weight 2000), and 13.4 parts by weight of a trimer of hexamethylene diisocyanate 6.0 parts by weight of hexamethylene diisocyanate (NCO / OH
A composite was obtained in the same manner as in Example 1 except that the ratio was 0.85), and the compression set was measured. As a result, it was 53%.

When the THF insoluble content of this composite was measured, it was 0.1 wt% or less.

Comparative Example 3 Polymer polyol (Nipporan 4067, manufactured by Nippon Polyurethane Co., Ltd., number average molecular weight 2000)
0 parts by weight and a trimer of hexamethylene diisocyanate (Coronate EH, trade name, manufactured by Nippon Polyurethane Co., Ltd.) 1
A mixture prepared by mixing 3.4 parts by weight (NCO / OH ratio = 0.85) for 1 minute was prepared, spread on a vat in a dryer at 120 ° C., and reacted for 10 hours to complete the reaction. 93.4 parts by weight of this urethane, 100 parts by weight of an ethylene-vinyl chloride copolymer (Rulon E-2800, manufactured by Tosoh Corporation) obtained by a suspension polymerization method, and 1 part of calcium stearate as a stabilizer Was mixed with a roll forming machine at 170 ° C., formed into a sheet, and a test piece was press-molded for a compression set (JIS K6301) and tensile (JIS K7113) test, and the compression set, tensile strength, and tensile elongation at break were measured. The results are shown below.

Compression set: 39% Tensile strength: 180 kg / cm ² Tensile elongation at break: 170%
wt%.

[0056]

According to the production method of the present invention, a PVC-PU composite excellent in compression set and mechanical strength can be obtained with high productivity without difficult pretreatment.

Claims (1)

(57) [Claims] 1. A polyvinyl chloride polymer is impregnated with a polymer polyol while stirring the polyvinyl chloride polymer with a mixer, and then a compound having three or more isocyanate groups (triphenylmethane-4,4 ', 4 "-
Triisocyanate, trimethylolpropane or hex
Reacting suntriol with excess polyisocyanate
Exclude the polyfunctional isocyanate obtained. ) Is impregnated with the polymer polyol and the isocyanate
The total amount of the compound having three or more groups is based on polyvinyl chloride.
30 parts by weight or more and 200 parts by weight based on 100 parts by weight of the polymer
Parts or less, wherein a cross-linked polyurethane is formed in the polyvinyl chloride-based polymer.