JP3379158B2 - Polyvinyl chloride resin composition and packing material - Google Patents

Description

BACKGROUND OF THE INVENTION DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention is a polyurethane, a composite resin composition comprising a polyvinyl chloride resin and a plasticizer
Packing material . 2. Description of the Related Art Conventionally, as a method for improving the load resistance of polyvinyl chloride resin, ie, the compression set, benzoyl peroxide, dicumyl peroxide, t
Polyperoxides such as organic peroxides such as -butyl peroxide, diamine compounds such as 1,4-tetramethylenediamine and 1,6-hexamethylenediamine, and sulfur compounds such as sulfur, tetramethylturum disulfide and triazinedithiol. A method by crosslinking vinyl chloride resin,
A method based on cross-linking of components such as diallyl phthalate, cross-linkable polyurethane or epoxy resin, and blending of cross-linked polyvinyl chloride resin which has been pre-cross-linked during polymerization or cross-linked NBR with good compatibility with polyvinyl chloride resin into polyvinyl chloride resin And a method of using a polyvinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked product with diisocyanate or the like. [0003] In these methods, when a polyvinyl chloride resin is crosslinked, a composition having good compression set can be easily obtained. The viscosity is remarkably increased, resulting in a material having poor moldability. In addition, (1) poor heat stability and easy coloring, (2) residual odor due to the residue of the crosslinking agent, and (3) a high degree of crosslinking has a large amount of plasticizer to achieve a predetermined hardness. , Etc. [0004] Among the above-mentioned methods, in the method using component crosslinking, this reaction often involves a radical reaction system, so that the same problem as described above occurs. [0005] Crosslinked polyvinyl chloride resin or crosslinked NBR
When blending with polyvinyl chloride resin,
(1) Physical properties such as tensile strength and elongation are remarkably reduced, related to their dispersibility in polyvinyl chloride resin.
(2) A large amount of plasticizer is required for adjusting the hardness. (3)
(4) Cross-linked NBR
There are problems such as poor weather resistance and heat aging resistance due to the butadiene component therein. Further, in the method of using a polyvinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked product by diisocyanate or the like, the reactivity is poor, and the improvement effect is small. Therefore, in recent years, a composite of a polyvinyl chloride resin and a polyurethane has attracted attention, and various methods have been proposed. For example, polyurethane is converted to a vinyl chloride monomer (V
CM), a method of obtaining a composite of a polyvinyl chloride resin and a polyurethane by polymerization of VCM, a method of producing a hydroxyl group-containing polyvinyl chloride resin by polymerization of VCM in the presence of a polyol, and a urethanization reaction of these. There are ways to get it. However, the composite of a polyvinyl chloride resin and polyurethane obtained by these methods has poor rubber elasticity and is not suitable for applications requiring these properties. On the other hand, as the packing material, a material excellent in molding workability and excellent in compression set is desired from the viewpoint of improving airtightness and the like. [0010] [0008] The present invention maintains the moldability, the excellent thermoplastic elastomer compression set
An object of the present invention is to provide a packing material . Means for Solving the Problems In view of the above-mentioned current situation, the present inventors have found that, in a composite of a polyvinyl chloride resin and polyurethane, the matrix is a polyvinyl chloride resin,
As a result of intensive studies on a phase separation material in which the dispersed phase is made of polyurethane, the present invention has been completed. That is, the present invention relates to a resin composition comprising a polyvinyl chloride resin, a crosslinked polyurethane and a plasticizer, wherein the matrix has a polyvinyl chloride resin and the dispersed phase has a phase separation structure of polyurethane. Wherein the tensile elastic modulus in the dynamic viscoelasticity measurement of the polyurethane used is 9 × 10 ⁵ dy in the range of 20 ° C. or more and 70 ° C. or less.
ne / cm ² or more 8 × is at 10 ⁷ dyne / cm ² or less, and Ma to compression modulus of the dispersed phase at 70 ° C.
Patent that the ratio of compression modulus of Torikusu phase comprising a thermoplastic elastomer resin composition is 0.4 to 1.8
It is a packing material . The details of the present invention will be described below. The polyvinyl chloride resin used in the present invention refers to at least one of vinyl chloride homopolymer resin, chlorinated vinyl chloride resin, and all monomers copolymerizable with vinyl chloride monomer. Vinyl copolymer resin (for example, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, etc.) obtained by random copolymerization or block copolymerization with a monomer, and a functional group such as a hydroxyl group in the above resin. It is a resin obtained by grafting or a resin obtained by reacting such a functional group with a reactive compound to form a graft bond, and may be a single product of these resins or a mixture of two or more types. The degree of polymerization of the polyvinyl chloride resin may be any, but from 400 to 8000 is preferred from the viewpoint of moldability, and more preferably from 500 to 5
000 or less. Further, a mixture of a polyvinyl chloride resin having a polymerization degree in the above range and a polyvinyl chloride resin having an arbitrary molecular weight may be used. The resin composition constituting the packing material of the present invention has a phase separation structure in which the matrix is a polyvinyl chloride resin and the dispersed phase is a crosslinked polyurethane. This situation is observed, for example, by observation with a transmission electron microscope (hereinafter referred to as TE).
M)).
If the phase separation structure is not confirmed by TEM, it indicates that the crosslinked structure of the polyurethane has spread throughout the entire system, and the moldability of the obtained resin composition is poor. Note that osnic acid is used for staining during TEM observation. As a method for obtaining such a phase-separated structure, for example, (1) a method in which a polyurethane obtained by reacting a polyol and an isocyanate compound in advance is finely crushed by mechanical pulverization or the like and mixed into a polyvinyl chloride resin; 2) A method in which a polyvinyl chloride resin, a polyol, an isocyanate compound, and a plasticizer are simultaneously heated and melt-kneaded to cause a urethane reaction, and a method using a material having inferior compatibility between the polyol and the polyvinyl chloride resin, (3) As in the case of (2), a method in which a polyurethane reaction is preferentially generated over the melt gelation of a polyvinyl chloride resin among the methods of heat-melt kneading and urethane reaction,
However, any method may be used to obtain the phase separation structure. In the resin composition constituting the packing material of the present invention, the plasticizer is present in both the matrix and the dispersed phase. That is, the packing material of the present invention is constituted.
That the resin composition matrix comprises a poly vinyl chloride resin and a plasticizer strictly, the dispersed phase comprising a crosslinked polyurethane and a plasticizer. The polyurethane used in the present invention is obtained from an isocyanate compound and a polymer polyol. At least one of the polyurethanes is a crosslinked polyurethane containing a polyfunctional component having three or more functional groups. At 70 ° C., which is the temperature at which is measured, the stress-strain curve in the compression test must be substantially the same as the polyvinyl chloride resin used as the matrix. Specifically, the ratio of the compressive modulus of the matrix phase to the compressive modulus of the dispersed phase obtained from the slope of the stress-strain curve is 0.4 or more and 1.8 or less, preferably 0.6 or more and 1.5 or less. And more preferably 0.8 or more and 1.2 or less. If this ratio is less than 0.4 or exceeds 1.8, the compression set properties of the obtained resin composition will deteriorate. The above-mentioned methods for making the elastic modulus of the matrix and the dispersed phase close to each other include, for example, (1) a method of manipulating the molecular weight of the polymer polyol, the number of functional groups of the polymer polyol or the isocyanate compound, and (2) a method of controlling the plasticizer. There are various methods such as a method of controlling the amount of addition. In the present invention, the blend amount of the polyurethane is preferably at least 30 parts by weight, more preferably at least 50 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. 3
If the amount is less than 0 parts by weight, the effect of improving the compression set of the obtained resin composition may be poor. From the viewpoints of cost performance, moldability, etc., the amount of polyurethane added is 90 parts by weight based on 100 parts by weight of the polyvinyl chloride resin.
It is preferably 0 parts by weight or less, more preferably 600 parts by weight or less. If the amount exceeds 900 parts by weight, the moldability of the obtained resin composition may be significantly deteriorated. The polymer polyol used to obtain the polyurethane is not particularly limited. One or more of polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, castor oil-based polyol, saponified EVA (ethylene-vinyl acetate copolymer) and the like are used. In addition, the polyester polyol shown here includes, for example, an ether ester-type polyester polyol obtained by condensation polymerization of diethylene glycol and adipic acid, and also includes a polyester polyol multifunctionalized with trimethylolpropane or the like. Further, polyether polyols, polycarbonate polyols, and polycaprolactone polyols also include polyfunctional polyols having three or more hydroxyl groups. On the other hand, the isocyanate compound used to obtain the polyurethane is not particularly limited. For example, 2,4- and 2,6-tolylene diisocyanate, m- and p-phenylene diisocyanate, 1-
Chlorophenylene-2,4-diisocyanate, 1,5
-Naphthalenediisocyanate, methylenebisphenylene 4,4'-diisoanate, m- and p-xylenediisoanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, etc. Triisocyanates of diisocyanate, triisocyanates such as 1,6,11-undecane triisocyanate, lysine ester triisocyanate, 4-isocyanatomethyl-1,8-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. Further, the polyurethane used in the present invention has a tensile elastic modulus in linear viscoelasticity measurement of 20 ° C. or more and 70 ° C.
9 × 10 ⁵ dyne / cm ² or more and 8 × in the following range
10 ⁷ dyne / cm ² or less, more preferably 1 × 10 ⁶
It is desirable to use polyurethane having a dyne / cm ² or more and 7 × 10 ⁷ dyne / cm ² or less. This means that when operating to equalize the modulus of the dispersed phase and the matrix,
If the elastic modulus of the polyurethane that is the dispersed phase is too low, a large amount of plasticizer is required for the polyvinyl chloride resin that becomes the matrix, so bleed-out tends to occur.If the elastic modulus of the polyurethane is too large, the matrix also becomes hard. ,
This is due to the loss of flexibility. As described above, in a blend of a polyvinyl chloride resin and a crosslinked polyurethane, a material in which the polyvinyl chloride resin and the polyurethane are phase-separated has excellent compression set characteristics due to the rubber-like properties of the crosslinked polyurethane. . The mechanism for improving the compression set by the crosslinked polyurethane will be described. When the compression set is improved by the crosslinked polyurethane, the driving force for the improvement of the compression set is derived from the strain energy of the crosslinked polyurethane immediately before the strain is released. The strain energy is defined as 1/2 of the product of the square of the strain and the elastic modulus, and the greater the strain energy, the greater the effect of improving the compression set. That is, in order to improve the compression set, two conditions of (1) increasing the strain and (2) increasing the elastic modulus of the crosslinked polyurethane immediately before releasing the strain are necessary. However, when the elastic modulus of the dispersed phase is passed through the matrix, the dispersed phase is less susceptible to deformation when the initial strain is applied, and the strain becomes small. Therefore, it is considered that the strain energy of the disperse phase at the time of release of strain becomes maximum when the matrix and the disperse phase have the same elastic modulus, and at this time, the effect of improving the compression set is greatest. The plasticizer which can be used in the present invention includes, for example, di-n-butyl phthalate, di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisodecyl phthalate Phthalic acid plasticizers such as diisooctyl phthalate, octyl decyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl isophthalate, di-2-ethylhexyl adipate (DOA), di-n-decyl adipate, adipine Diisodecyl acid, dibutyl sebacate, di-sebacate
Aliphatic ester plasticizers such as 2-ethylhexyl, pyromellitic plasticizers such as trioctyl trimellitate and tridecyl trimellitate, tributyl phosphate, tri-2-ethylhexyl phosphate, 2-ethylhexyl diphenyl phosphate, phosphorus Phosphate plasticizers such as tricresyl acid, epoxy plasticizers such as epoxy soybean oil,
Chlorinated paraffins, high molecular weight plasticizers such as polyester high molecular weight plasticizers, high molecular weight compounds having a glass transition temperature lower than that of polyvinyl chloride resin and having plasticizing ability for polyvinyl chloride resin, etc. And one or more of these can be used. The above-mentioned plasticizer is appropriately selected according to the purpose.For example, a high-molecular-weight plasticizer may be used for improving heat resistance and non-migratory property, and dibutyldiglycol adipate or the like may be used for improving oil resistance. Good. Further, in order to improve the fluidity, an adipate plasticizer and a sebacate plasticizer may be added. The amount of the plasticizer to be added is as follows.
It is preferably from 10 to 200 parts by weight, more preferably from 25 to 1 part by weight, per 100 parts by weight.
50 parts by weight or less. If the amount is less than 10 parts by weight, moldability may be impaired, and if it exceeds 200 parts by weight, bleed out may occur. The polyvinyl chloride resin composition constituting the packing material of the present invention contains an inorganic material such as calcium carbonate or talc which is usually added to the polyvinyl chloride resin to such an extent that its performance is not extremely reduced. Fillers, flame retardants such as antimony trioxide and zinc borate, modifiers such as partially cross-linked polyvinyl chloride, partially cross-linked acrylonitrile-butadiene rubber (NBR), processing aids such as acrylic resins, metals A heat stabilizer represented by a salt, hydrotalcite or the like can be added as needed. When another resin is added, a compatibilizing agent for the present resin composition and another resin can be used in combination as the third component. EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples. The method of measuring the compression set according to JIS K6301 in the examples is as follows. A test piece is inserted into a test mold set in advance at 70 ° C., and a strain of 25% is given, and then 22 hours elapse. Thereafter, the strain is released, the sample is left at room temperature for 30 minutes, and the change in the sample thickness before and after the test is measured. Example 1 Polyester polyol obtained by condensation polymerization of 3-methyl-1,5-pentanediol and adipic acid (Co., Ltd.)
100 parts by weight (manufactured by Kuraray, trade name: Kurapol P4010, number average molecular weight: 4000) and an isocyanurate-modified isocyanurate of hexamethylene diisocyanate (polyfunctional isocyanate compound, average number of functional groups: 3.6 / 1 molecule) 10 parts by weight (NCO / OH (isocyanate index) = 1.0) (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate HX), and DBTDL (dibutyltin dilaurate) 26.7PP as a catalyst
M was mixed and left in an oven at 120 ° C. for 2 hours to form a polyurethane. 0.5 thickness from this sample
A rectangular test piece having a size of 5 mm, a width of 5 mm and a length of 25 mm was cut out to obtain a test piece for measuring the dynamic viscoelasticity of polyurethane.
Separately, polyurethane was finely crushed by a roll forming machine set to a surface temperature of 150 ° C. to prepare a sample for blending.
In addition, polyvinyl chloride resin (Shin-Etsu high polymerization degree PVC T
K-2500W, average degree of polymerization: 4500, 100 g of Shin-Etsu Chemical Co., Ltd.), 2 g of barium stearate as a stabilizer, 1 g of zinc stearate, an amine supplement (BP-331 manufactured by Nissan Ferro-Organic Chemical Co., Ltd.) ) 1.5 g,
100 g of di-2ethylhexyl phthalate (DOP),
After 100 g of polyurethane finely crushed for blending was sufficiently mixed at room temperature, the mixture was kneaded with a roll forming machine set to a surface temperature of 150 ° C. The kneading time was 15 minutes. The composite thus obtained was press-molded to have a thickness of 12.70 ± 0.13 mm for JIS K6301 compression set. The DOP uneven distribution amount of the matrix and the dispersed phase was determined according to the method described separately in <Measurement of plasticizer uneven distribution amount>. Based on the uneven distribution amount obtained here, a mixture of polyvinyl chloride resin and DOP corresponding to the matrix is mixed by a roll forming machine so that the thickness becomes 12.70 ± 0.13 mm for JIS K6301 compression set measurement. Was press-molded. Further, a polyurethane corresponding to the dispersed phase and DO are used.
In order to obtain a mixture of P, a polymer polyol, an isocyanate compound, DOP, and DBTDL26.7 as a catalyst
The PPM was sufficiently mixed, poured into a mold having a depth of 12.70 ± 0.13 mm, and left in an oven at 120 ° C. for 2 hours to obtain a material corresponding to the dispersed phase. In addition, the kind, grade, etc. of the raw materials were all the same as those described in this example. [0035] matrix corresponding mixture with a dispersed phase equivalent of mixing of
Compression speed 0.2mm the compound at 70 ° C. respectively
/ Min was subjected to a compression test and a stress-strain test was performed. The elastic modulus of each material was determined from the initial slope of the stress-strain curve. <Measurement of the amount of uneven distribution of the plasticizer> DOP was blended as a plasticizer at the time of preparing polyurethane with 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, and 50 parts by weight of 100 parts by weight of polyurethane. It was poured into a 1 mm thick mold and cured by heating to form a sheet, which was used as a sample for a migration test. Furthermore, polyvinyl chloride resin 100
DOP is 50 parts by weight, 60 parts by weight, 7 parts by weight
The stabilizer was further added to each of 0 parts by weight, 80 parts by weight, and 90 parts by weight, and the mixture was sufficiently kneaded by a roll kneader to form a sheet having a thickness of 1 mm by a press molding machine. did. In order to obtain information on the uneven distribution of DOP in the dispersed phase and the matrix, 10 parts by weight of D
90% for OP-added sample and polyvinyl chloride resin
Attach the sample to which DOP was added by 70 parts by weight
A migration test was performed. Similarly, a sample of 20 parts by weight of DOP for polyurethane, a sample of 80 parts by weight of DOP for polyvinyl chloride resin, a sample of 30 parts by weight of DOP for polyurethane and a sample of 70 parts by weight of DOP for polyvinyl chloride resin, A sample of 40 parts by weight of DOP for polyurethane and a sample of 60 parts by weight of DOP for polyvinyl chloride resin, a sample of 50 parts by weight of DOP for polyurethane and a sample of 50 parts by weight of DOP for polyvinyl chloride resin, Were bonded to each other, and a migration test was performed at 70 ° C. The test time was 24 hours. The transferability was evaluated by the weight change rate, and the DOP that minimized each weight change rate was determined.
To the matrix and dispersed phase in equilibrium
It was determined as the uneven distribution of P. Comparative Example 1 In place of the polyester polyol used in Example 1, 100 parts by weight of a polyester polyol having the same composition and having a number average molecular weight of 500 (Kuraray Co., Ltd., trade name: Kurapol P510), and an isocyanate compound were used. 7
A composite material was obtained by the same operation as in Example 1 except that 9.8 parts by weight (NCO / OH = 1.0) was used. Comparative Example 2 Instead of the polyester polyol used in Example 1, 100 parts by weight of a polyester polyol having the same composition and having a number average molecular weight of 6000 (Kuraray Co., Ltd., trade name: Clapol P6010), and an isocyanate compound were used. A composite material was obtained by the same operation as in Example 1 except that 6.0 parts by weight (NCO / OH = 0.9) was used. The material obtained as described above was subjected to an evaluation test described below. Table 1 shows the results. (Measurement of Compression Set) Measured according to JIS K6301. After an initial strain of 25% and a temperature of 70 ° C. for 22 hours, the strain was released and the residual strain was measured. (Measurement of Compression Elastic Modulus) A compression test was performed using a Tensilon tensile tester. The test temperature is 70 ° C,
The compression speed was 0.2 mm / min. (Measurement of Tensile Elastic Modulus) Viscoelasticity analyzer R which is a measuring device based on the non-resonant type forced vibration method
The tensile storage modulus (E ′) at 23 ° C. was measured by using SAII (Rheometrics Far East) at a measurement frequency of 10 Hz and a measurement mode of “tensile”. All measurements were performed in the linear region. (Confirmation of phase structure) The obtained composite material was treated with Os
Exposed to the vapor of O _4, stained, finish this ultra thin section under 0.1 micron atmosphere -100 ° C. at ultramicrotome. This was transferred to an electron microscope DEOL JEM-20.
Observation was performed at an accelerating voltage of 200 kV using 00FX. Upon this observation, it was confirmed that the polyurethane component dyed into OsO ₄ was a dispersed phase having a size of 0.1 to 100 μm. [Table 1] As described above, the packing material of the present invention
The material is made of a thermoplastic elastomer with excellent compression set.
You .

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 27/06 C08L 75/04-75/16 C08G 18/62 C09K 3/10

Claims (1)

(57) [Claims] (1) A resin composition comprising a polyvinyl chloride resin, a cross-linked polyurethane and a plasticizer, wherein the matrix is a polyvinyl chloride resin and the dispersed phase is a polyurethane having a phase separation structure. A tensile elastic modulus in the dynamic viscoelasticity measurement of the polyurethane used is 20 ° C. or more and 70 ° C.
9 × 10 ⁵ dyne / cm ^{2 to} 8 in the range of not more than 8 ° C.
× 10 ⁷ dyne / cm ² or less, and the ratio of compression modulus of the matrix phase is made of a thermoplastic elastomer resin composition is 0.4 to 1.8 for the compression modulus of the dispersed phase at 70 ° C. Packing material characterized by
Fees .