JPH0524921B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a vinyl chloride polymer in which a polyol is homogeneously dispersed or partially grafted. More specifically, by reacting with an isocyanate compound, vinyl chloride polymer (PVC
The present invention provides a method for producing a polyol-containing vinyl chloride polymer that yields a composite of a urethane polymer (hereinafter referred to as PU) and a urethane polymer (hereinafter referred to as PU). [Industrial Application Fields] PU has excellent abrasion resistance, low-temperature properties, oil resistance, gasoline resistance, etc., and is easy to process and mold.Furthermore, depending on the combination of constituent raw materials, it can be used in a variety of materials ranging from flexible to hard. It is used in various fields because it is easy to obtain arbitrary physical properties. On the other hand, PVC is a versatile thermoplastic resin with excellent processability, and is widely used industrially for pipes, corrugated sheets, sash, films, sheets, leather, wire coverings, hoses, and daily miscellaneous goods. It is used. However, PU and PVC each have the following drawbacks. PU has a high water absorption rate and poor hydrolysis resistance and heat resistance. Thermosetting PU overcomes these drawbacks considerably, but imposes severe restrictions on moldability and processability. Regarding PVC, 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. In soft polyvinyl chloride, a large amount of low molecular weight plasticizer is used, so the volatilization and migration of the plasticizer,
It has the disadvantage of poor flexibility, cold resistance, and solvent resistance due to elution with solvents. The present invention provides a method for producing a vinyl chloride polymer that can be easily composited with PU. By using this method, it is possible to utilize the characteristics of both PVC and PU while compensating for the drawbacks of each. Achieving improvements in various physical properties, and using normal PVC processing methods without any difficult pre-treatment,
It can be processed in exactly the same way as regular PVC. Therefore, it can be used in many industrial fields, but it can be broadly divided into the following fields of use based on its main characteristics: (1) As hard polyvinyl chloride with improved impact resistance...
Structural materials (2) As unplasticized polyvinyl chloride...materials for films, leather, hoses, medical field (3) As soft polyvinyl chloride with improved oil resistance and abrasion resistance...materials for special electric wires, sheathed wires, automobiles Parts (4) As polyvinyl chloride with a crosslinked structure...
Agricultural use, packaging sheets, foam sheets, mechanical parts, packing materials (5) As heat-resistant improved polyvinyl chloride...flooring materials,
Automobile parts (6) Water-resistant improved polyurethane includes flooring materials, shoe soles, etc. Examples include, but are not limited to, the above examples. [Prior Art] Conventionally, composite materials have been proposed to compensate for the drawbacks of PVC and PU, and have been used in tubes, hoses, sheets, industrial parts, etc. The following methods are known for compounding, but all of them are limited by the range of workability and application, and require many complicated steps to create the compound. Also, the pretreatment during molding is complicated. (1) Blending PVC and thermoplastic PU In order to obtain a mixture with excellent physical properties at low cost, blending thermoplastic PU (hereinafter referred to as TPU) and PVC has been proposed, and is actually used in some fields. has been done. However, typically TPU is
Because they are in the form of flakes or pellets of about mm size, they have poor workability when blended with PVC powder, and when mixing additives such as stabilizers, the particle size is different, resulting in non-uniformity, resulting in molded products. There are problems such as insufficient mechanical strength and poor appearance. Another method is to powder TPU and blend it with PVC powder, but it is often difficult to powder TPU, which is relatively soft and matches the physical properties required for ordinary mixed resins. Furthermore, due to the physical properties required of the mixed resin, 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 PU JP-A-58-40312, 58-42611, 59-
As stated in Publication No. 37019, etc., VCM
Grafting by suspension polymerization of soluble TPU and VCM has been proposed, and compositions have been proposed. In these compositions, it is necessary to dissolve TPU in VCM and mix it uniformly, so the composition and amount of PU to be blended must be restricted. For example, PU is thermoplastic and has a low softening point, so it is limited to a special type that contains almost no hard segments in its molecular chain. (3) Polyurethane composition produced by reaction in the presence of PVC powder A method as described in JP-A-58-5357 has been proposed. In this case, a difficult process is required to obtain a uniform dispersion state of the PVC powder in the composition, and if the amount of PV powder added is large, the viscosity of the reaction mixture increases significantly, and the preparation of the composition is difficult. is difficult. In addition, because the reaction mixture is unstable, the pot life is short.
Preservation in this state is difficult. [Problems to be Solved by the Invention] In view of this situation, the present inventors have attempted to improve the heat-resistant shape retention, abrasion resistance, and low-temperature impact resistance of PVC without impairing its workability, and at the same time to improve the reinforcing effect. As a result of extensive research into a method for obtaining composite resin with improved tensile properties, we have found that it is easier than the conventional method.
We have discovered a vinyl chloride polymer that can be combined with PU and provides a composite with excellent processability and physical properties. [Means for solving the problem] The present invention is based on VCM or VCM.
A monomer mixture of a monomer copolymerizable with VCM and VCM is added to the VCM in an amount of 5 to 200% by weight based on VCM.
An object of the present invention is to provide a method for producing a vinyl chloride-based polymer in which a polyol is homogeneously dispersed or partially grafted by polymerization in an aqueous medium in the presence of a polyol that can be dissolved in a polyol. The vinyl chloride polymer obtained in the present invention is obtained in powder form and can be easily composited with PU by reacting with an isocyanate compound.
Provides PVC/PU composites that are almost completely homogeneously blended or partially chain bound. The details will be explained below. The polyols used in the present invention include short chain polyols such as aliphatic, alicyclic, aromatic substituted aliphatic or polycyclic dihydroxy compounds, trihydroxy compounds, tetrahydroxy compounds, etc. -ethanediol, 1,2-
Propanediol, 1,4-butanediol, butenediol, 1,6-hexanediol, 1,
10-decamethylene diol, 2,5-dimethyl-
2,5-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, bis(β-hydroxyethoxy)benzene, p-xylene diol, dihydroxyethyltetrahydrophthalate, trimethylolpropane, glycerin, 2-methyl Selected from propane-1,2,3-triol, 1,2,6-hexanetriol, pentaerythritol, etc. As long-chain polyols, polyester polyols, polyether polyols, polycarbonate polyols, vinyl polyols, diene polyols, castor oil polyols, silyune polyols, polyolefin polyols, copolymers thereof, and the like are used. These long chain polyols are preferably used in a molecular weight range of 300 to 10,000, more preferably
It is in the molecular weight range of 500-8000. Examples of polyester polyols include succinic acid, glutaric acid, adipic acid, gelaic acid, sebacic acid, dotecanoic acid, phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid, and itacon. A dicarboxylic acid selected from acids, etc.
Those obtained by reacting hydroxy compounds selected from the short chain polyols mentioned above are used. Another way to obtain polyester diol is
β-propiolactone, vivalolactone, δ-valerolactone, ε-caprolactone, methyl-ε
- It is also possible to react a lactone compound such as caprolactone, dimethyl-ε-caprolactone, trimethyl-ε-caprolactone with a hydroxy compound selected from the above-mentioned short chain polyols, etc. As the polyether polyol, polytetramethylene glycol is used. , polyethylene glycol,
Polypropylene glycol, polyoxyprolene glycol, etc. are used. As the polycarbonate polyol, one 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-1,6-hexamethylene carbonate, poly-2,2'-bis(4-hydroxyhexyl)propane carbonate, and the like are industrially produced and easily available. Another method for obtaining polycarbonate polyols is the so-called phosgene method (or solvent method). Others, β-hydroxyethyl acrylate,
Vinyl polyols such as acrylic polyols obtained by copolymerizing acrylic monomers with hydroxyl groups such as β-hydroxyethyl methacrylate and acrylic esters, poly(1,4-
Polyols that can be dissolved in VCM are used, such as polybutadiene polyols such as (butadiene) and poly(1,2-butadiene), castor oil polyols such as polypropylene glycol ricinoleate, silicone polyols, and polyolefin polyols. It is also possible to use some of the short chain and long chain polyols mentioned above in combination. The polymerization ratio of polyol to VCM is
It ranges from 5.0% to 200% by weight, and this ratio can be selected as required. If it exceeds 200%, the dispersion during polymerization will become unstable, and it will be difficult to obtain fine particles even if a large amount of suspending agent or emulsifying agent is present during polymerization.
Moreover, the polymer at this time has the problem of fusion between particles during drying. Furthermore, a feature of the present invention is that VCM is polymerized in an aqueous medium in the presence of a polyol to produce a powdered polyol-containing vinyl chloride polymer, but the polymerization reaction is carried out using water as a dispersion medium. As long as the polymerization method is used, any of suspension polymerization, fine suspension polymerization, and emulsion polymerization may be employed. For suspension polymerization and drug suspension polymerization, known oil-soluble polymerization initiators such as aromatic diacyl peroxide, aliphatic diacyl peroxide, peroxy esters of organic acids, peroxydicarbonates, and azo compounds are used. It can be done. On the other hand, in emulsion polymerization, a water-soluble polymerization initiator such as hydrogen peroxide, potassium persulfate, and ammonium persulfate is used. Emulsifiers used during polymerization include alkyl sulfonates, alkylaryl sulfonates, alkyl alcohol sulfate ester salts,
One or more types of ordinary anionic surfactants such as fatty acid salts and dialkyl sulfosuccinic acid hydrochloride can be mentioned, but these salts include:
Alkali metal salts are common. In addition to anionic surfactants, nonionic surfactants such as glyceryl esters, glycol esters, or sorbitan esters of higher fatty acids, higher alcohol condensates, higher fatty acid condensates, polypropylene condensates, etc., or emulsifying aids One or more of higher alcohols such as cetyl alcohol and lauryl alcohol, higher fatty acids such as lauric acid, palmitic acid, and stearic acid or their esters can also be used in combination with the anionic surfactant. As the suspension stabilizer, partially saponified polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxymethylcellulose, gelatin, fatty acid ester of polyethylene glycol, etc. are all suitable, and one or more of these may be used in combination. Is possible. Furthermore, during polymerization, processing stabilizers and auxiliary agents for PVC, such as epoxy stabilizers, metal soaps, etc., may be added in advance. Furthermore, in the present invention, it is also possible to use VCM in combination with other vinyl monomers that can be copolymerized. Examples of these vinyl monomers include vinylidene monomers such as vinylidene chloride and vinylidene fluoride, methyl acrylate, ethyl acrylate, butyl acrylate,
Esters of actylic acid such as octyl acrylate, cyanoethyl acrylate, etc., esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc., styrene and styrene derivatives such as methystyrene, vinyltoluene, chlorostyrene, etc. , vinyl monomers such as acrylonitrile, ethylvinibenzene, and vinylnaphthalene, and dialkenes such as butadiene, isoprene, fluoroprene, and the like. Polymerization is carried out in a conventional manner, i.e. in a conventional polymerization autoclave, from 30°C to 70°C, preferably from 40°C.
Performed in a temperature range of 70°C. The polyol is usually added before the VCM is added. Polyols usually dissolve easily in VCM and do not require any particular dissolution reaction. According to the method of the present invention, compounding with polyurethane is easier than with conventional methods, and a composite resin with excellent processability and physical properties, such as heat-resistant shape retention, abrasion resistance, and low-temperature impact resistance, can be obtained. It will be done. The present invention will be further explained below with reference to Examples, but the present invention is not limited by the Examples. Example 1 In a stainless steel autoclave equipped with 50 stirring blades, 30 kg of pure water and a polyol of butanediol/adipic acid condensate [molecular weight 1000] (Nitsuporan 4009, trade name manufactured by Nippon Polyurethane Industries Co., Ltd.) 6
Kg, as a suspension stabilizer, average saponification degree 75 mol%,
After adding 100 g of partially saponified polyvinyl alcohol with an average degree of polymerization of 1700 and 6 g of α,α'-azobis-2,4-dimethylvaleronitrile, the autoclave was sealed and the oxygen in the polymerization system was evacuated. to this
After charging 20 kg of VCM, stirring was started, the temperature was raised to 60°C, and the polymerization reaction was started. Polymerization was stopped when the autoclave internal pressure decreased to 7.0Kg/ ^cm2 ,
After collecting unreacted VCM, the polymer was dehydrated and dried. The polymerization results and physical properties of the polymer are summarized in Table 1 together with those of other Examples. Examples 2 to 7 The same procedure as in Example 1 was carried out except that the type and amount of polyol added were changed as shown in Table 1.
Table 1 shows the polymerization results and physical properties of the polymer. Example 8 30 kg of pure water, 90 g of sodium lauryl sulfate as an emulsifier (trade name: Emar 10, manufactured by Kao Atlas Co., Ltd.), and a polyol as shown in Table 1 were placed in a stainless steel autoclave equipped with 50 stirring blades, and the autoclave was sealed. After evacuating oxygen from the polymerization system, 15 kg of VCM was charged and kept at 60° C. with stirring, and after 1 hour, 12 g of potassium persulfate was added and polymerized. The internal pressure of the autoclave is 7.0
Polymerization was stopped when the temperature decreased to Kg/cm ² . Thereafter, the emulsion was subjected to salting out treatment, and the polymer was dried and ground. Table 1 shows the polymerization results and physical properties of the polymer. Application example 1 1250 parts by weight of the polyol-containing vinyl chloride polymer obtained in Example 1 was charged into a Warner type kneader with an internal volume of 2, and organic tin malate was added while stirring.
A mixture of 10 parts by weight of barium stellarate and 30 parts by weight was added, and liquid methylene bisphenylene-4,4'-diisocyanate (MTL-C, trade name manufactured by Nippon Polyurethane Kogyo KK, NCO content) was added. 28.6wt%) was added to 71 parts by weight,
Blend in for 30 minutes at room temperature to obtain a powdered compound. This compound was kneaded for 10 minutes with a hot roll at 150°C to create a sheet with a thickness of approximately 0.8 mm. Physical properties were measured using this sheet. The blending ratio of compaction, the temperature of the hot roll, and the measurement results of physical properties are summarized in Table 2 together with other examples. Application example 2 1250 parts by weight of the polyol vinyl chloride-containing polymer obtained in Example 1 was charged into a Warner type kneader with an internal capacity of 2, and while stirring, an isocyanurate trimer of hexamethylene diisocyanate (product manufactured by Nippon Polyurethane Kogyo KK) was added. Name, Coronate EH) 100
A mixture of 50 parts by weight of DOP and 30 parts by weight of organic tin malate and 10 parts by weight of barium stearate was added thereto, and blending was performed at room temperature for 30 minutes to obtain a powdery compound. This compound was kneaded for 10 minutes with a heated roll at 160°C to create a sheet with a thickness of 0.8 mm. Application Examples 3 to 5 Sheets were prepared in the same manner as in Application Examples 1 and 2 by changing the type of isocyanate compound and the blending ratio. Comparative Examples 1 to 3 General vinyl chloride powder (Toyo Soda Kogyo KK
A stabilizer and a plasticizer were dry blended using Ryuton 800BK (trade name: Ryuton 800BK), a sheet was prepared using a heated roll, and the physical properties were measured. Table 2 shows the physical property measurement results along with the blending ratio and hot roll temperature. Comparative example 4 Nituporan 4009 (manufactured by Nippon Polyurethane Industries KK,
1,4-butanediol adipate = 1000)
1000g was put into a Warner type kneader with an internal capacity of 2, and the mixture was stirred and the internal temperature was maintained at 80°C. After this,
280 g of MTL-C was added to carry out a urethanization reaction. The internal temperature rose to 135°C, and a rubbery PU resin was obtained after 60 minutes. This resin was cooled to about -5°C in a freezer and then ground in a grinder to obtain flakes (PU resin A). Use this flake to make general vinyl chloride powder (Toyo Soda Kogyo Co., Ltd.)
A blended sheet with Lieuron 800BK manufactured by KK was created using a heated roll. The blending ratio was the same as that of Application Example 1. The temperature of the hot roll was changed to 130°C, 150°C, and 190°C, and the workability and sheet shape in each case were compared with Application Example 1. The blending ratios and results are summarized in Table 3. In addition, the physical property values of the vinyl chloride polymer shown in each Example and Comparative Example were measured by the following method. (1) Average particle size Measured using a Coulter counter in water. Operations and equipment are discussed in T. Allen, "Particle Size Measuremet", Chapter 13, 2nd edition (1975), Chapman and Hall, London. (2) Bulk specific gravity Measured according to JIS-K-6721. (3) PVC content Calculated from the results of chlorine analysis. The re-sediment is
The experiment was carried out three times using THF-MeOH system. (4) Grafting rate Calculated using the following formula. Grafting rate = 100-B/100-A x 100 (%) Here, A and B are before and after reprecipitation, respectively.
Indicates PVC content (%). (5) Hydroxyl value Since it was impossible to measure using the method according to JIS-K-0070, the following method was used. A sample is urethanized with excess tolylene diisocyanate (TDI) in a solvent containing equal amounts of cyclohexanone and tetrahydrofuran. After the reaction, the residual NCO group was measured and calculated from that value. The NCO group content was measured according to JIS-K-1556.

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Claims (1)

[Scope of Claims] 1. In the production of vinyl chloride polymers, vinyl chloride monomers (hereinafter referred to as VCM) or monomer mixtures of VCM and monomers copolymerizable with VCM, mainly consisting of VCM. , 5 to 200% by weight relative to VCM
A method for producing a polyol-containing vinyl chloride polymer, which comprises polymerizing in an aqueous medium in the presence of a VCM-soluble polyol. 2. The method according to claim 1, wherein the polyol is an aliphatic, cycloaliphatic, aromatically substituted aliphatic, or heterocyclic dihydroxy compound, trihydroxy compound, or tetrahydroxy compound. 3. The polyol according to claim 1, wherein the polyol is a polyester polyol, a polyether polyol, a polycarbonate polyol, a vinyl polyol, a diene polyol, a castor oil polyol, a silicone polyol, an olefin polyol, or a copolymer thereof. Method. 4. The method according to claim 1, wherein the polyol has a molecular weight of 10,000 or less, more preferably 8,000 or less.