JPS621715A - Production of composite material of polyvinyl chloride-polyurethane type - Google Patents

Abstract

PURPOSE:To obtain the titled composite material having improved mechanical properties, wherein two polymers are uniformly and finely dispersed, by blending separately polyvinyl chloride powder with an isocyanate compound and an active hydrogen compound, mixing the prepared two blends and molding the mixture under heating. CONSTITUTION:(A) (i) Vinyl chloride-containing (co)polymer having >=300 polymerization degree is blended with (ii) an isocyanate compound (e.g., 2,4-tolylene diisocyanate, etc.) by the use of a ribbon blender, etc. (B) On the other hand, (B) the polyvinyl chloride powder of the component i is similarly blended with a compound (e.g., 1,2 ethanediol, etc.) containing Zerewitinoff active carbon, both the blends are mixed in a molar ratio of an isocyanate group to the active hydrogen group of 0.5-10 by a heating molding machine such as calender processing machine, etc., and the reaction is advanced to give the aimed composite material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining a composite of a vinyl chloride polymer (hereinafter referred to as PVC) and a polyurethane polymer (hereinafter referred to as PU).

More specifically, the present invention relates to a method for efficiently producing a molded product of a compound in which PvC and PU are homogeneously mixed by mutually intertwining chains by advancing a urethanization reaction simultaneously with heat molding.

[Industrial application field]

PVC is a versatile thermoplastic resin with excellent processability and is widely used for pipes, corrugated sheets, satsies, films, sheets, leather, electrical wire coverings, hoses, boots, and daily miscellaneous goods. However, so-called hard polyvinyl chloride, which does not use much plasticizer such as dioctyl phthalate (hereinafter referred to as DOP), has a drawback in impact resistance, especially brittleness at low temperatures.

Because soft polyvinyl chloride uses a large amount of low-molecular-weight plasticizers such as DOP, it suffers from poor flexibility, cold resistance, and solvent resistance due to volatilization, migration, and elution of the plasticizer with solvents. be.

On the other hand, PU has excellent wear resistance, low-temperature properties, oil resistance, gasoline resistance, etc., and it is easy to obtain any physical property from soft to hard by combining the constituent raw materials, so it is used in various fields. used in

The aforementioned PVC has good processability and is inexpensive, so it is used in many fields as a general-purpose structural material, but in recent years, with the development of industry and technology, it has improved its impact resistance, heat resistance, shape retention, and abrasion resistance. There is a strong demand for improvements in mechanical properties such as

The molded product of the present invention is produced by homogeneously blending PvC and PU to form a structure in which chains are intertwined with each other.
It takes advantage of the features of PVC and PU while compensating for their shortcomings and improving various physical properties.

Moreover, it is characterized in that it can be processed in a so-called one-shot process using commonly used processing machines for plastics and elastomers, without performing difficult pre-treatments.

Therefore, it can be used in industrial fields, and its main characteristics make it useful for pipes, corrugated sheets, sashes, mechanical parts, packing, floor materials, self-gthXIL parts, medical supplies, etc. It is not limited to this.

[Conventional technology]

Conventionally, composites have been proposed to compensate for the drawbacks of PVC%PU, and have been used for cheap products, hoses, sheets, industrial parts, etc.

The following methods are known for compounding, but all of them are limited in terms of processability and range of application, and require many complicated steps to prepare the powder. It also has disadvantages such as complicated pretreatment during molding.

(1) Blending PVC and thermoplastic polyurethane In order to obtain a mixture that is inexpensive and has excellent physical properties, it has been proposed in some fields to blend thermoplastic polyurethane (hereinafter referred to as TPU) and PvC. actually used. However, since TPU is usually in the form of flakes or pellets, when blended with PvC powder,
In addition, when mixing additives such as stabilizers, the particle size is different, resulting in non-uniformity, resulting in problems such as insufficient mechanical strength and poor appearance of the molded product. be.

There is also a method of powdering TPU and blending it with PVC powder, but it is often difficult to powder TPU, which is comparatively soft and matches the physical properties required for ordinary mixed resins.

Furthermore, due to the physical properties required for the mixing surface layer, the melting temperatures of TPU and PVc are often different, which makes mixing difficult and has the disadvantage of poor workability.

(2) Graft polymer of PVC and thermoplastic polyurethane JP-A-58-40312, 58-42611, 58
As described in publications such as No.-37019, grafting by suspension polymerization of TPO and VCM, which are soluble in vinyl chloride monomer (hereinafter referred to as VCM), has been proposed, and m-parabolites have been provided. Since these compositions require TPU to be dissolved in VCM and mixed uniformly, the composition and amount of PU must be restricted. For example, PU is a thermoplastic and has a low softening point. For this reason, they are limited to special types that contain almost no hard segments in their molecular chains.

(3) Polyurethane composition obtained by reaction in the presence of PVC powder.
Some methods have been proposed.

In this case, a difficult process is required to obtain a uniform dispersion of the Pvc powder in the composition.

Furthermore, if the amount of PvC powder added increases, the viscosity of the reaction mixture increases significantly, making it difficult to manufacture the composition.

Furthermore, since the reaction mixture is unstable, its pot life is short and it is difficult to store it in this state.

(4) Production of polyurethane in PV (1987)
A method as described in Japanese Patent No. 39464 has been proposed. In this case, in order to complete the polyurethanization reaction in the PvC particles, the PU acid component is a thermosetting type, or a so-called hard segment polyurethane consisting only of a short chain polyol and a short chain polyisocyanate, or a nodal polyurethane. If a hard type with a high proportion of segments is used, the resulting alloy cannot be molded.

Even if molding was possible, PvC and PU would not be homogeneously dispersed,
Therefore, sufficient mechanical strength cannot be obtained and the appearance is poor, making it practically unusable.

Furthermore, even if a composition that is sufficiently compatible with PVC is selected as the PU acid component, the structure of the molded product will be that of PVC.
The result is very similar to that obtained by a simple blend of PVC and PU, and a structure in which PVC and PU are entangled with each other cannot be expected.

[Problem that the invention seeks to solve]

The present invention aims to improve the disadvantages of PVC without impairing the processability of PvC by combining PvC and PU.

Conventionally, the main purpose of combining PvC and PU has been to realize non-migration, soft PVC, and a soft PU composition has been selected. The present invention is made by homogeneously dispersing (hard segment) PU and/or thermosetting PU with PvC, which was previously difficult to achieve, and by adopting a molecular structure in which chains are intertwined with each other, it is hard and has heat-resistant shape retention. The aim is to obtain a composite material that simultaneously improves abrasion resistance, low-temperature impact resistance, and oil resistance.

Of course, depending on the physical properties desired in the present invention, it is also possible to obtain a soft composite by selecting a soft PU composition and/or using a plasticizer in combination.

[Means for solving problems]

That is, the present invention produces a composite molded product of polyvinyl chloride and polyurethane by molding a mixture of powdered polyvinyl chloride, an isocyanate compound, an active hydrogen compound, and, if necessary, a plasticizer and additives using a heat molding machine. The present invention provides a method for producing a polyvinyl chloride-polyurethane composite, which comprises blending an isocyanate compound and an active hydrogen compound separately mixed with powdered polyvinyl chloride. .

Isocyanate compounds are highly active and react with active hydrogen compounds in a short time under heating to produce 1,i(1M7 urethane).

Powdered PvC, apart from so-called paste PvC, is manufactured to be as porous as possible in order to improve plasticizer absorption and promote gelation during processing. Therefore, the normal P
Plasticizers other than those used as plasticizers for VC can also be absorbed depending on their compatibility with PvC.

The present invention provides a powder in which an isocyanate compound and an active hydrogen compound are independently impregnated into the PVCA pores.
By mixing arbitrary amounts and heating and molding, PVC melts during molding, and at the same time the isolation between the isocyanate compound and the active hydrogen compound is broken, and the urethanization reaction starts and progresses in the molten PvC solution, forming PvC and PvC. A complex with PU is obtained.

Therefore, it is usually not possible. Thermosetting PU and hard segment) PU can be efficiently converted into almost completely homogeneous PVC.
It can be combined with

If you choose a thermosetting type with PU acid component, PVC and PU
It takes an IPN (interpenetrating network) structure formed by

Furthermore, by mixing other resins, fillers, etc., and using a blend, these materials can also be composited at the same time.

Surprisingly, when thermoforming the compound based on the method of the present application, even if it is filled into a thermoforming machine such as an injection molding machine and molded,
It has been found that there is no sudden reaction in the molding machine that results in gelation, and there is no decrease in moldability over time.

The polyvinyl chloride used in the present invention is a vinyl chloride-containing polymer with a degree of polymerization of 300 or more, or a copolymer whose main component is vinyl chloride, such as vinyl chloride-vinyl acetate copolymer, chloride Vinyl-ethylene
Examples include vinyl acetate (EVA) copolymer. Additives such as stabilizers, lubricants, and colorants can be added to the polyvinyl chloride and the like in advance, if necessary.

In addition, in the present invention, a polymer blend vinyl chloride is used in which a thermoplastic resin or rubber other than polyurethane that is compatible with the polyvinyl chloride, such as acrylic resin, styrene resin, ABS resin, nitrile rubber, etc., is blended with polyvinyl chloride in advance. You can also.

The isocyanate compounds used in the present invention include 2.4- and 2.6-tolylene diisosif*
-) sm- 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'-methylenebis(cyclohexyl isocyanate), inphone diisocyanate, trimethyl hexa Diisocyanates such as methylene diisocyanate, triisocyanates such as 1,6,11-undecane triisocyanate, lysine ester triisocyanate, 4-isocyanate methyl-1,8-octamethyl diisocyanate, or polyphenyl dimethane polyisocyanate. Reaction of the above-mentioned isocyanate compounds with polyfunctional isocyanates such as, dimers or trimers of these isocyanate compounds, the above-mentioned short-chain and long-chain polyols, or water and active hydrogen compounds such as amino compounds. An isocyanate compound such as an isocyanate compound having a terminal isocyanate group obtained by is used.

In addition, as the isocyanate compound, the above-mentioned isocyanate compound is stabilized with a blocking agent such as an active methylene compound, oxime, lactam, phenol, furkylphenol, or basic nitrogen-containing compound, and the isocyanate group is regenerated by heating. Also included are boot-squeezed isocyanate compounds.

Further, as the isocyanate compound, it is also possible to use a mixture of several types of the above-mentioned isocyanate compounds, and it is also possible to use a mixture of the above-mentioned isocyanate compounds dissolved in a solvent.

The active hydrogen compound used in the present invention is a compound having a Solewitinoff active hydrogen atom and generally has a molecular weight of 5.
0-10. Cj OO, which is a compound having at least one hydrogen that reacts with isocyanate, i.e., a compound having a human-xyl, 7-mino, or thiol group; examples include water/polyols 1 polyamines, polythiols, amino alcohols, etc. It will be done.

Polyols include aliphatic, short-chain polyols,
Alicyclic, aromatic, substituted aliphatic or heterocyclic dihydroxy compounds, trihydroxy compounds, tetrahydroxy compounds, etc., such as 1,2-ethanediol, 1,2-propanediol, 1,4-butanediol, Butynediol, 1,6-hexanediol, 1,10-decamethylenediol, 2,5-dimethyl-2,5-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexane dimetatool, bis(β-
human-oxyethoxy)benzene, p-coconut diol, dihydroxyethyltetrahydrophthalate, trimethylpropane, glycerin, 2-methiflepropane-1,2,3-)liol, 1,2,6-hexanediol, Selected from Pentaerythritol, etc.

Long chain polyols include polyester polyol, polyether polyol, polycarbonate polyol,
Vinyl polyols, diene polyols, castor oil polyols, silicone polyols, polyolefin polyols, copolymers thereof, and the like are used.

These long chain polyols range from 300 to i o, o o
.

It is preferable to use a molecular weight in the range of 500 to 500 s, o o o.

Examples of polyester polyols include succinic acid, geltaric acid, 7-divic acid, 7-gelaic acid, sebacic acid,
A dicarboxylic acid selected from dodecanoic acid, phthalic anhydride, inphthalic acid, tetra-L-phthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid, itaconic acid, etc. and a human selected from the above-mentioned short chain polyols. A compound obtained by reacting with an xyl compound is used.

Another method for obtaining polyester polyols is β-propiolactone, bivalolactone, δ-noclerolactone, 5-caprolactone, metifle-6-cabrolactone, dimethyl-6-caprolactone, trimethyl-ε-
It is also possible to react a lactone compound such as caprolactone with a hydroxy compound selected from the short chain polyols mentioned above.

As the polyether polyol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, dipropylene glycol in polio, etc. are used.

As the polycarbonate polyol, a polycarbonate obtained by a transesterification method from a hydroxy compound selected from the above-mentioned short chain polyols and diallyl carbonate, dialkyl carbonate, or ethylene carbonate is used. For example, poly-11-1,6-hexamethylene carbonate, poly-2,2'-bis(4-hydrooxyhexyl)prol(carbonate), etc. are produced industrially and can be easily handled by nine people.

Another method to obtain polycarbonate polyol is
The so-called phosgene method (or solvent method) can be used.

In addition, vinyl polyols such as acrylic polyols obtained by copolymerizing acrylic monomers with silyl groups such as β-hydroxyethyl acrylate, β- and silyl ethyl methacrylate, and acrylic esters; Polybutadiene polyols such as (1,4-butadiene) and poly(1,2-butadiene), castor oil polyols such as polypropylene glycol lysyllate, silicone polyols, and polyolefin polyols are used.

It is also possible to use some of the above-mentioned short-chain and long-chain polyols in combination.

The polyamine used in the present invention includes 4.4
'-Diaminodiphenylmethane, 3.3'-diter 12
−． 4.4'-diaminodiphenylmethane, 1.2-bis(2-aminophenylthio)ethane, 3,5-diethyltoluenedi7mine, 3.3',5.5'-tetraisopropylmethylenediamine, Examples include 1,3-di(aminomethyl)benzene, ethylenediamine, hexamethylenediamine, and the like.

The above-mentioned polyamines having a high freezing point are preferably used after being dissolved in a plasticizer such as DOP.

The plasticizer used in the present invention is usually PvC
Phthalate esters, dibasic acid esters, non-sulfuric acid esters, glycol esters, and polymer plasticizers used as plasticizers, such as diethyl phthalate, dibutyl phthalate, dioctyl phthalate, and phthalate. Examples thereof include butyl lauryl acid, di2-ethylhexyl 7-dibenate, di-2-ethylhexyl azelaate, tricresine phosphate, tributoxyethyl phosphate, dibutyl diglyfluoride adibate, modified polypropylene 7-dipate, and the like.

The additives used in the present invention include stabilizers, lubricants,
Coloring agents, urethane reaction catalysts, fillers, extenders, etc.

To impregnate PvC with an isocyanate compound or an active hydrogen compound, use a ribbon blender or Warner type kneader.
, Pony mixer, Henschel mixer, and other commonly used mixers can be used.

Powdered PvC is put into a mixer, a stabilizer for polyvinyl chloride is added thereto, and the mixture is stirred and mixed. An isocyanate compound is added to this, and PvC powder impregnated with the isocyanate compound is obtained by continuing mixing.

Mixing should be done at room temperature, or in some cases between 60 and 120 degrees Celsius.
It may be carried out at a high temperature.

On the other hand, the preparation of PvC powder impregnated with an active hydrogen compound is carried out in almost the same manner as the preparation of PvC powder impregnated with an isocyanate compound.

When impregnating PvC with polyol, etc., it is desirable to heat the polyol, etc. to 80° C. or higher in advance. Also,
It is preferable that the urethanization reaction catalyst and/or the PU stabilizer be mixed in advance with the active hydrogen compound and added.

Also, Pv of isocyanate compound or active hydrogen compound
When impregnating C, a plasticizer can be added at the same time. For example, it is also possible to dissolve an isocyanate compound and/or an active hydrogen compound separately in a liquid plasticizer such as DOP, and then add them to PvC. be.

The required amounts of the PvC powder impregnated with an isocyanate compound and the PvC powder impregnated with an active hydrogen compound thus obtained are put into the above-mentioned mixer, and if necessary, new PVC, other resins and By adding additives, fillers, colorants, stabilizers, etc. and mixing and stirring,
A reactive bedform composition is obtained which contains an isocyanate compound and an active hydrogen compound in PvC pores in a separated manner.

The blending ratio of PvC impregnated with an isocyanate compound and PvC impregnated with an active hydrogen compound is such that the ratio of the isocyanate compound impregnated in PvC to the active hydrogen compound is 0. Preferably, it is in the range of 5 to 10.

The reactive molding composition obtained in this way can be molded with good processability using a hot molding machine such as an extrusion molding machine, an injection molding machine, or a calendar processing machine, and undergoes a urethanization reaction at the same time as the hot molding. This process progresses to complete the combination of PvC and PU.

〔Effect of the invention〕

As is clear from the above description, the following effects can be obtained according to the present invention.

(1) To obtain a composite in which PVC and PU are homogeneously finely dispersed and intertwined with each other, and have excellent heat resistance, shape retention, abrasion resistance, low temperature impact resistance, oil resistance, etc. I can do it.

(2) Since PvC impregnated with an isocyanate compound and PvC impregnated with an active hydrogen compound can be stored separately, the molding composition can be easily formulated to obtain desired physical properties, and is storage stable. Sex is also good.

(3) Because the polyurethanization reaction proceeds simultaneously with molding, hard segment) PU and/or thermosetting fi
It is possible to combine PU and PvC, and by adopting an IPN structure, it can exhibit strong physical properties, and it can also be easily combined with other fillers, so it has a wide range of applications.

Furthermore, it is advantageous in terms of process reduction and energy cost compared to conventional blend types.Using these characteristics, it can be used in many industrial fields, but more specifically, For example, by using the molding composition of the present invention for slurry wear-resistant pipes, pulp valve seats, etc. in fields where PVC pipes are conventionally used, products with higher performance can be manufactured using conventional equipment. be able to.

Furthermore, in the field of corrugated sheets, it is possible to obtain products that do not crack when nailed at low temperatures.

Furthermore, in the field of flooring materials and automobile parts, by using a thermosetting composition of the PU acid component, it is possible to provide a material that is flammable and has a high heat distortion temperature.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 (1) 1000 parts by weight of polyvinyl chloride powder with a degree of polymerization of 700 was added to the contents ff12I! Put it into the Warner type Neegoo,
While stirring at high speed, iog parts of barium stearate and 3 parts by weight of organic tin laurate were added and the mixture was heated to 70°C. Then, 200 ml of hexamethylene diisocyanate (hereinafter referred to as MDI) was heated to 70°C.
Parts by weight were added and mixed with stirring for 15 minutes while maintaining the mixing temperature at 70°C. Easily flowable powder mixture (A
-1) was obtained.

(2) Polyvinyl chloride powder ioo with a degree of polymerization of 7'00.

Weight part contents f2I! Put it into the Warner type Neegoo,
While stirring at high speed, 10 parts by weight of barium stearate and 30 parts by weight of organic tin laurate were added, and the mixture was heated to 10 parts by weight.
Heated to 0°C. Next, add 0.4 parts by weight of Djibouti to 200 parts by weight of ethylene glycol (hereinafter referred to as EG) in advance. Restin dilaurate (hereinafter referred to as DBTDL) was mixed and the mixture heated to 100°C was added to the mixture at a mixing temperature of 100°C.
Stirring and mixing were performed for 20 minutes while maintaining the temperature. An easily flowable powder mixture (B-1) was obtained.

(3) 1000 parts by weight of (A-1) and 370 parts by weight of (
B-1) and the internal capacity, 2I! The mixture was put into a Warner type kneader and mixed and stirred at room temperature for 5 minutes to obtain a powdery compound that could easily flow.

(4) Using the mold pound obtained in (3), a flat plate with a thickness of 2 and 3 sides was produced using an injection molding machine (manufactured by Nippon@Hagane KK, JlooS).

The injection molding conditions are as follows.

This flat plate could be nailed at -5°C and did not cause any cracks. Physical properties were measured using this flat plate. The measurement results are summarized in Table 1.

Example 2 (1) Polyvinyl chloride powder with a degree of polymerization of 700 1000
Contents by weight: 21! Put it into the Warner type Neegoo,
While stirring at high speed, 10 parts by weight of barium stearate and 30 parts by weight of organic tin laurate were added, and the mixture was reduced to 7 parts by weight.
Heated to 0°C. MR-200 was then heated to 70°C.
(Nippon Polyurethane Kogyo KK @ trade name, polymethylene polyphenylene polyisocyanate, NCO content 7.31
200 parts by weight (t% by weight) were added and mixed with stirring for 15 minutes while maintaining the mixing temperature at 70°C. An easily flowable powder mixture (A-2) was obtained.

(2) 1,4-butanediol (hereinafter BG
) 200ffiffi part was used, and the others were as in Example 1.
A powder mixture (B-2) was obtained in the same manner as in (2).

(3) Contents Jt2t of (A-2) of 1000 fold fl and part of 333 fold 21 (B-2)! The mixture was poured into a Warner type Negoo and mixed and stirred at room temperature for 5 minutes to obtain a powdery compound that could easily flow.

(4) (3) Using the prepared compound, a flat plate was prepared in the same manner as in Example 1, and the physical properties were measured. The measurement results are summarized in Table 1.

Example 3 α) Tolylene diisocyanate (hereinafter T
200 parts by weight (referred to as DI), and the rest were as in Example 1,
(1) A powdered mixture (A-3) was obtained in the same manner as in Example 7.

(2) Pour 1000 parts by weight of polyvinyl chloride powder with a degree of polymerization of 1000 into a Warner type Negoo with a content of FF12J,
While stirring at high speed, 10 parts by weight of barium stearate were added and the mixture was heated to 100°C.

Next, add a portion of DOP10031i and leek rti57 in advance.
-4010 (Product name manufactured by Nippon Polyurethane Industries KK; Poly(1,4-butanediol adipate) MW=2000
)250m! l: parts, 30 parts by weight of BG, 30 parts by weight of organic tin laurate, and 0.4 parts by weight of DBT D L were mixed, and the mixture heated to 100°C was added to the mixture at a mixing temperature of 1.
Stirring and mixing were performed for 20 minutes while maintaining the temperature at 00°C. An easily flowable powder mixture (B-3) was obtained.

(3) 340tjt parts of (A-3) and 1000 parts by weight of (B-3) were put into a Warner type kneader with an internal capacity of 2A, and mixed and stirred at room temperature for 5 minutes to form an easily fluid powder. compound was obtained.

(4) Using the dung pound obtained in (3),
A flat plate was produced in the same manner as in Example 1, and physical properties were measured. The measurement results are summarized in Table 1.

Incidentally, each physical property was measured as follows.

(1) Hardness: Measured using a D-type derometer hardness tester according to ASTM D2240r.

■) Normal physical properties: According to JISK6740.

(3) Abrasion resistance: According to ASTM D 1044.

(4) Flammability + oxygen index according to JIS K7201 was measured.

(5) Vicat softening temperature; according to JISK6740.

Comparative example 1 (1) Content'! 500 parts by weight of Nitsuboran-4010 and 60 parts by weight of BG were placed in an IC21 Warner type Nigu, and the mixture was stirred and mixed at an internal temperature of 80°C for 5 minutes.

Next, add 8 parts of D B T D L O and 8 parts of TD1400 heated to 60°C while stirring at high speed.
Pour in the weight part. After stirring and kneading for 1 hour, the contents are cooled and pulverized as is. A powdered polyurethane thermoplastic resin fli (C-1) was obtained.

(2) 1fi degree 1000 f) Polychlorinated hini z
1,000 parts by weight of the powder was put into a Warner-type Negoo with an internal capacity of 21, and while stirring at high speed, 10 parts by weight of barium stearate was added, and the mixture was heated to 100°C.

Next, a mixed solution of 100 parts of DOP heated to 100° C. and 30'iJL parts of organic tin laurate was added and stirred for 200 minutes.

An easily flowable powder mixture (D-1) was obtained.

(3) 235JJNi: Part (C-1) and 1000
1 fi part of (D-1) was put into a Warner type Negoo with an internal capacity of 21 kg, and stirred for 5 minutes at room temperature to obtain an easily flowable powdery compound.

(4) A flat plate was prepared in the same manner as in Example 1 using the dung pound obtained in (3). No homogeneous plates were obtained.

Comparative Example 2 Powder mixture (B) obtained in the same manner as in Example 2 (■)
-2) 1200 parts by weight, content 21! The temperature of the contents was raised to 70° C. while stirring. Next, parts by weight of MR-20027 mentioned above were added, and stirring and mixing was continued for about 1 hour at a temperature of 110°C.

The contents were then cooled to room temperature to obtain a powdered compound.

Using this, a flat plate was created in the same manner as in Example 2.

The molding process was difficult and a homogeneous flat plate could not be obtained. P
Gelled products of U were scattered, and the surface was poor.

Table 1

Claims (1)

[Claims] In a method of obtaining a composite molded product of polyvinyl chloride and polyurethane by molding a mixture of powdered polyvinyl chloride, an isocyanate compound, an active hydrogen compound, and, if necessary, a plasticizer and additives using a heat molding machine. A method for producing a polyvinyl chloride-polyurethane composite, which comprises blending a mixture of an isocyanate compound and an active hydrogen compound separately with powdered polyvinyl chloride.