JP3391069B2 - Injection molding material - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding material comprising a composite resin composition containing a polyurethane, a polyvinyl chloride resin and a plasticizer, and the material is rubber. Boots molded by injection molding without impairing the basic properties,
It is a material that can be used for grommets, packing, sealing materials, automobile exterior members, civil engineering, building materials, sports equipment, and the like. 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
Chloride with 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. Cross-linking of vinyl resin, component cross-linking of diallyl phthalate, cross-linkable polyurethane or epoxy resin, and blending of pre-cross-linked cross-linked vinyl chloride resin or cross-linked NBR with good compatibility with vinyl chloride resin into vinyl chloride resin A known method is a method of using a vinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked product with diisocyanate or the like. In these methods, when a vinyl chloride resin is crosslinked, a composition having good compression set can be easily obtained, but on the other hand, the melt viscosity of the obtained composition is low. It increased significantly, making injection molding impossible. 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. When a reactive plasticizer is used, it is often a radical reaction system, so that the same problem as described above occurs. [0005] When a crosslinked polyvinyl chloride resin or a crosslinked NBR is blended with a polyvinyl chloride resin, it is necessary to (1) relate to their dispersibility in the polyvinyl chloride resin; Remarkable decrease in physical properties,
(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 vinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked product with diisocyanate or the like, the reactivity is poor, so that 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 (VC
M) to obtain a composite of a vinyl chloride resin and a polyurethane by polymerization of VCM, a method of producing a hydroxyl group-containing vinyl chloride resin by polymerization of VCM in the presence of a polyol, and a method of obtaining these by a urethanization reaction. is there. However, the composite of the 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, demands for materials excellent in injection moldability typified by large-sized injection molding and precision injection molding, and rubber-like properties typified by compression set have been increasing in recent years. In addition, a material having excellent injection moldability, particularly a material having a low melt viscosity is desired. [0010] An object of the present invention is to provide an injection molding material having excellent compression set. Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned current situation, and as a result, have completed the present invention. That is, the present invention provides a polyvinyl chloride resin (1), water
Polymer polyol having two or more acid groups and hexamethyl
A modified isocyanurate of diisocyanate
A resin composition comprising a polyurethane obtained allowed urethane reaction (2) and a plasticizer (3), the sea by transmission electron microscopy - island type phase separation structure is observed, and the island of the isolation structure The polyurethane dispersed phase having a size of 0.01 to 100 μm and a tensile modulus in the linear viscoelasticity measurement of polyurethane (2) in the range of 20 ° C. to 70 ° C. is 7 × 10 ⁶ dyne.
/ Cm ² or more and 8 × 10 ⁷ dyne / cm ² or less, and an adipic acid-based plasticizer as a plasticizer (3) is used in an amount of 10 to 80 parts by weight based on 100 parts by weight of the polyvinyl chloride resin (1)
Parts by weight or less and di-n-butyl phthalate, di-phthalate
2-ethylhexyl, di-n-octyl phthalate, lid
Diisodecyl luate, diisooctyl phthalate, phthalic acid
Butylbenzyl, di-2-ethylhexyl isophthalate
Le, dioctyl sebacate, polyester high molecular weight
Group consisting of plasticizer, epoxidized soybean oil, and chlorinated paraffin
An injection molding material comprising a resin composition containing one or more plasticizers selected from the group consisting of a polymer polyol having a molecular weight of 300 to 1500, which is a constituent component of the polyurethane (2). The details of the present invention are described below. The polyvinyl chloride resin (1) used in the present invention is at least one of vinyl chloride homopolymer resins, chlorinated vinyl chloride resins, and all monomers copolymerizable with vinyl chloride monomers. Vinyl chloride copolymer resin (for example, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, etc.) obtained by random copolymerization or block copolymerization with the above-mentioned monomer. Examples of the resin include a resin obtained by grafting a functional group, a resin obtained by reacting a reactive compound with the functional group and graft-bonding the resin, and may be a single resin or a mixture of two or more resins. The degree of polymerization of the polyvinyl chloride resin (1) is not particularly limited, and is from 400 to 5,000 in view of moldability.
Or less, more preferably 500 or more and 4000 or less, still more preferably 800 or more and 3000 or less. Further, a polyvinyl chloride resin having an arbitrary molecular weight may be blended with a polyvinyl chloride resin having a polymerization degree in the above range. The polyurethane (2) used in the present invention has a tensile modulus in linear viscoelasticity measurement of not less than 7 × 10 ⁶ dyne / cm ^{2 and not} more than 8 × 10 ⁷ d in the range of 20 ° C. to 70 ° C.
yne / cm ² or less, more preferably 2 × 10 ⁷ dyne
/ Cm ² or more and 7 × 10 ⁷ dyne / cm ² or less are used. By using such a polyurethane, the compression set of the present invention is improved and the moldability is also improved. In order to further improve the compression set of the material of the present invention, the compression set of the polyurethane (2) used alone is preferably 40 or less, more preferably 35 or less. The compression set referred to here is
This is a value measured according to the method of JIS K6301 compression set, the measurement temperature is 70 ° C., and the time for giving strain is 22 hours. The polyurethane (2) has two hydroxyl groups.
Hexamethylene diiso with polymer polyol having above
Urethane conversion of isocyanurate-modified cyanate
It is a polyurethane obtained by reaction, and it is effective to use a polyurethane having a network structure as the polyurethane (2) from the viewpoint of improving the compression set of the material of the present invention. That is, the content of THF dissolved in a good solvent such as tetrahydrofuran (THF) of polyurethane (2) is 10%.
It is desirable to use the following. In order to further improve the compression set of the material of the present invention, the ratio of the compressive modulus of the matrix phase to the compressive modulus of the dispersed phase at 70 ° C. is desirably 0.4 or more and 1.8 or less. . In order to improve the tensile strength of the material of the present invention, it is preferable to use a polyurethane (2) having excellent compatibility with the polyvinyl chloride resin (1) to be used. Examples of such polyurethane (2) include polyester-based polyurethane, polycaprolactone-based polyurethane, polycarbonate-based polyurethane, and ether-ester-based polyurethane containing as a main component a compound obtained by ester-bonding an ether-based diol represented by diethylene glycol and a dicarboxylic acid. Furthermore, natural organic compounds having a hydroxyl group represented by cellulose and saponified EVA
(Ethylene-vinyl acetate copolymer), such as a compound obtained by a urethane reaction of a synthetic organic compound having a hydroxyl group and an isocyanate compound. Of these, the use of polyester-based polyurethane, polycaprolactone-based polyurethane, polycarbonate-based polyurethane, or ester-ether-based polyurethane is particularly preferable because the tensile strength of the material of the present invention is significantly improved. It is also possible to control the isocyanate index (number of isocyanate groups / number of hydroxyl groups) of the polyurethane (2) in the material of the present invention. In general, polyurethane is obtained by a polyaddition reaction between a compound having a hydroxyl group and a compound having an isocyanate group, but the number of functional groups contained in each compound is not fixed, and there are various polyurethanes. For example, since a saponified EVA (ethylene-vinyl acetate strong polymer) or the like contains many hydroxyl groups in one molecule, the gelation point generated by the reaction with the isocyanate compound has a considerably low isocyanate index. It is difficult to uniquely determine the optimal isocyanate index depending on the number of functional groups of the compound used in this way, but it is preferably 0.6 or more and 1.2 or less. Is prevented. When the polyurethane (2) to be used is obtained by urethane reaction of a polymer polyol with a compound having three or more isocyanate groups, the molecular weight of the polyol which is one of the components of the polyurethane is not particularly limited. However, a material obtained by using a polymer polyol having an average molecular weight of 300 or more and 1500 or less is preferable because it has excellent compression set and injection moldability. The ratio of the polyvinyl chloride resin (1) to the polyurethane (2) used in the present invention is not particularly limited. However, in order to improve the compression set characteristics of the resulting material, the polyvinyl chloride resin (1) is used. The amount of the polyurethane (2) is preferably at least 20 parts by weight, preferably at least 30 parts by weight, and more preferably at least 45 parts by weight with respect to 100 parts by weight. From the viewpoint of cost performance, the amount of the polyurethane (2) is preferably 900 parts by weight or less, more preferably 300 parts by weight or less, and further preferably 150 parts by weight or less based on 100 parts by weight of the polyvinyl chloride resin (1). It is desirable to do. Further, an adipic acid plasticizer must be added as a plasticizer (3) to the material of the present invention. Adipic acid-based plasticizers are the most effective plasticizers in terms of cost performance and decrease in melt viscosity (that is, excellent injection moldability), and when trying to reduce melt viscosity without using this plasticizer, cost performance and Undesirable in terms of plasticizer bleed-out. Particularly, di-2-ethylhexyl adipate is most preferably used from the viewpoint of cost performance. The amount of the plasticizer (3) to be added is 10 to 80 parts by weight, preferably 20 to 70 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin (1). If the addition amount is less than 10 parts by weight, the effect of lowering the melt viscosity by the adipic acid-based plasticizer is poor, and
If it exceeds 0 parts by weight, the plasticizer may bleed out. In the material of the present invention, the plasticizer
(3) Di-n-phthalic acid for imparting flexibility
Butyl, di-2-ethylhexyl phthalate, diphthalic acid
-N-octyl, diisodecyl phthalate, diiphthalate
Sooctyl, butylbenzyl phthalate, diisophthalate
-2-ethylhexyl, dioctyl sebacate, polyether
Stell based high molecular weight plasticizer, epoxidized soybean oil, chlorinated
One or more plasticizers selected from the group consisting of
To use. The material of the present invention includes inorganic fillers such as calcium carbonate and talc, which are usually added to polyvinyl chloride resin, and antimony trioxide and zinc borate, to such an extent that their performance is not extremely reduced. A flame retardant, a partially crosslinked polyvinyl chloride, a modifier such as a partially crosslinked acrylonitrile-butadiene rubber (NBR), and a processing aid represented by an acrylic resin can be added as required. Further, a hydrolysis inhibitor represented by carbodiimide, which is usually added to polyurethane, a chlorine-based, nitrogen-based, fungicide represented by silver-zeolite, a UV stabilizer and the like may be added as necessary. It is possible. It is also possible to blend this material with other resins to improve the rubbery properties of other resins. In this case, a compatibilizer of the material of the present invention and another resin can be used in combination as the third component. The method for producing the material of the present invention is not particularly limited, and any method can be adopted. Specifically, the following method is exemplified. (A) A method in which a polyurethane (2) is finely crushed by freeze pulverization or the like and then blended with a polyvinyl chloride resin (1). In this case, an apparatus used for blending is arbitrary, and examples thereof include a roll, a Banbury mixer, and an extruder. (B) A method in which a polyvinyl chloride resin (1), a polyol and an isocyanate compound are added to a solvent such as tetrahydrofuran (THF) to cause a urethane reaction in the solvent, and then the solvent is evaporated. (C) A method of obtaining a composite material by heating and melting a polyvinyl chloride resin (1), a plasticizer (3), a polymer polyol, and an isocyanate compound under a shearing force. In particular, by using the method (C), the material of the present invention is preferable because strength represented by tensile strength is improved. The material of the present invention has a sea-island type phase-separated structure when observed with a transmission electron microscope (TEM) after staining with a staining agent such as OsO ₄ , and ,
The size of the polyurethane dispersed phase, which is the island part, is 0.01
Must be no less than 100 microns.
If the size of the dispersed phase exceeds this range, the processability of the material of the present invention will be significantly reduced. In order to improve the formability, the size of the dispersed phase is preferably from 0.03 to 80 microns, more preferably from 0.05 to 60 microns. The material of the present invention can be molded by an injection molding machine usually used for thermoplastic resins. And the molded article obtained in this way is excellent in compression set. EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples. Example 1 Polyester polyol obtained by condensation polymerization of 3-methyl-1,5-pentanediol and adipic acid (Co., Ltd.)
Kuraray product name, Kurapol P510, number average molecular weight 5
00) 56.8 parts by weight and 36.6 parts by weight of isocyanurate-modified hexamethylene diisocyanate (trifunctional isocyanate compound) (trade name: Coronate HX, manufactured by Nippon Polyurethane Co., Ltd.) (NCO / OH ratio = 0) .8
5) Further, 26.7 PPM of DBTDL (dibutyltin dilaurate) was mixed as a catalyst, and the mixture was left in an oven at 120 ° C. for 2 hours to produce a polyurethane. 0.5mm thick, 5mm wide, 25mm long from this sample
Was cut out and used as a sample for measuring dynamic viscoelasticity. In addition, the obtained polyurethane was finely crushed by freeze pulverization to obtain a composite material. Polyurethane fine powder 9 thus obtained
3.4 parts by weight, ethylene-vinyl chloride copolymer obtained by a suspension polymerization method (Ryuron E-2800,
Average polymerization degree: 2750, 100 parts by weight of Tosoh Corporation) 2 parts of barium stearate, 1 part of zinc stearate as stabilizer, amine supplement (BP-331, trade name of Nissan Ferro-Organic Chemical Co., Ltd.) 1 0.5 part, 50 parts by weight of di-2ethylhexyl phthalate (DOP) and 50 parts by weight of dioctyl adipate (DOA) were thoroughly mixed at room temperature. This was kneaded with a roll forming machine having a surface temperature set at 150 ° C. for 15 minutes to obtain a composition. After completion of the kneading, the obtained roll sheet was finely crushed by sheet pelletizing and injection-molded into a flat plate of 2.1 mm. In addition, JI
A test piece for measuring SK6301 compression set was used. Example 2 A target composition was obtained and molded in the same manner as in Example 1 except that 50 parts by weight of DOP, 30 parts by weight of DOA and 20 parts by weight of dioctyl sebacate were used. Example 3 60 parts by weight of DOP, 40 parts by weight of DOA, and a polyester high molecular weight plasticizer (Adekaizer PN28 manufactured by Asahi Denka Kogyo KK) as a high molecular weight plasticizer
Except that 30 parts by weight of 0) was used, the same operation as in Example 1 was carried out to obtain a target composition, which was molded. Example 4 A desired composition was obtained and molded by the same operation as in Example 1 except that 75 parts by weight of the polyurethane after freeze-milling was added. Example 5 A polyester polyol having the same composition as the polyester polyol used in Example 1 and having a number average molecular weight of 1000 (Kuraray Co., Ltd., trade name: Clapol P1)
010) 69.4 parts by weight and 24.0 parts by weight of a hexamethylene diisocyanate trimer (NCO / OH ratio = 0.
85) Except for using, the same procedure as in Example 1 was carried out to obtain a target composition, which was molded. Example 6 Example 9 except that 43.1 parts by weight of hexamethylene diisocyanate trimer (NCO / OH ratio = 1.0) was used.
A target composition was obtained by the same operation as described above, and was molded. Example 7 The target composition was prepared in the same manner as in Example 1 except that a vinyl chloride homopolymer (Ryuron TH-1300, average degree of polymerization: 1300, manufactured by Tosoh Corporation) was used as the polyvinyl chloride resin. This was molded. Example 8 As a polyvinyl chloride resin, an ethylene-vinyl chloride copolymer (Ryuron E-2200, average degree of polymerization: 2200,
A target composition was obtained and molded by the same operation as in Example 1 except that Tosoh Corporation was used. Comparative Example 1 A composition was obtained and molded by the same operation as in Example 1 except that no polyurethane was used. Comparative Example 2 438 g of the polyvinyl chloride resin used in Example 1 in a Banbury mixer, 12 g of barium stearate and 5.4 g of zinc stearate as stabilizers, an amine supplement (Nissan Ferro-Organic Chemical Co., Ltd.) Product name BP-331)
7.5 g was charged and stirred at a constant rotation speed. Separately from this, a polymer polyol (Nipporan 406 manufactured by Nippon Polyurethane Co., Ltd.) which has been previously kept at 70 ° C.
7, number average molecular weight 2000) 350 g and DOP219
g of DOA and 219 g of DOA, and 58.6 g of a trimer of hexamethylene diisocyanate (NCO / OH ratio =
0.85), dibutyltin dilaurate 0.0 as a catalyst
3 g was charged, mixed for 1 minute, and then poured from the Banbury mixer inlet. The reaction and mixing time is now 15
After a few minutes, a composition was obtained. The composition obtained was molded in the same manner as in Example 1. Comparative Example 3 A composition was obtained and molded in the same manner as in Example 1 except that 100 parts by weight of DOP was used without using DOA. Comparative Example 4 A composition was obtained and molded in the same manner as in Example 1 except that a pulverized product of polyurethane which did not pass through a 2 mm mesh after being mechanically pulverized was blended. Comparative Example 5 A composition was obtained in the same manner as in Example 1 except that 1000 parts by weight of a freeze-ground polyurethane was blended.
This was molded. Comparative Example 6 A composition was obtained and molded by the same operation as in Example 1 except that 90 parts by weight of DOA was used. Comparative Example 7 Polyurethane thermoplastic polyurethane (Milactran P-39, manufactured by Nippon Miractran Co., Ltd.) was used as the polyurethane.
A composition was obtained and molded in the same manner as in Example 1 except that (RSOP) was used. Comparative Example 8 64.9 parts by weight of a polyester polyol and 28.5 parts by weight of an isocyanate compound (NCO / OH ratio: 0.5
8) A desired composition was obtained and molded by the same operation as in Example 1 except that the composition was used. The composition obtained above was evaluated by the following method. Table 1 shows the results. (Evaluation of compression set) The compression set was 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. (Evaluation of bleed of plasticizer) The test piece for permanent compression set was allowed to stand at room temperature for one week, and the surface was observed to evaluate the bleed of the plasticizer. (Confirmation of phase structure) The sample was exposed to the vapor of OsO ₄ and stained, and this was subjected to −10 with an ultramicrotome.
Finish in 0.1 micron ultra-thin section at 0 ° C. This was taken with an electron microscope JEOL JEM-2.
Observation was performed at an acceleration voltage of 200 kV using 000FX. At the time of this observation, it was confirmed that the component of the polyurethane dyed into OsO ₄ was a dispersed phase having a size of 0.1 to 100 μm. (Measurement of Dynamic Viscoelasticity) Viscoelasticity measuring device DV
Using E-V4 (manufactured by Rheology Co., Ltd.), the tensile storage elastic modulus (E ′) at 23 ° C. was measured at a measurement frequency of 10 Hz, a measurement mode of tensile, and a strain of 1% or less in a linear region. (Injection molding) Injection molding machine (I manufactured by Toshiba Corporation)
S50EP) was used for injection molding. The molding conditions are as shown below. Temperature H1: 110 ° C H3: 160 ° C H2: 130 ° C NH: 160 ° C Pressure Injection pressure: 55 kg / cm ² (gauge pressure) Holding pressure: 40 kg / cm ² (gauge pressure) Cooling Mold temperature: 50 ° C Time Injection time 1 second holding time: 1.5 seconds Cooling time: 20 seconds Mold 2.1 mm thick flat plate As described above, the material of the present invention is an injection molding material having excellent compression set and suppressing bleeding of the plasticizer.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 27/06 B29C 45/00-45/84 C08L 67/02-67/03 C08L 75/04-75 / 16

Claims (1)

(57) [Claims] (1) A polyvinyl chloride resin (1) having two hydroxyl groups.
Hexamethylenediyl
Urethane conversion of modified isocyanurate of cyanate
A resin composition comprising a polyurethane (2) and a plasticizer (3) obtained by reacting , wherein a sea-island type phase-separated structure is observed by transmission electron microscopy, and an island portion of the separated structure is provided. And the size of the polyurethane dispersed phase is 0.
01 micron or more and 100 microns or less, and the tensile elastic modulus in the linear viscoelasticity measurement of polyurethane (2) is 20
In the range of ^{70 ℃ ℃ 7 × 10 6 dyne} / cm 2
Or 8 × is at 10 ⁷ dyne / cm ² or less, polyvinyl chloride resin (1) a plasticizer with respect to 100 parts by weight (3) as adipic acid plasticizer 10 parts by weight or more 80 parts by weight or less, and phthalic acid Di-n-butyl, di-2-ethyl phthalate
Lehexyl, di-n-octyl phthalate, diiphthalate
Sodecyl, diisooctyl phthalate, butyl phthalate
Undil, di-2-ethylhexyl isophthalate, SEBASHI
Dioctyl phosphate, polyester high molecular weight plasticizer, epoxy
Selected from the group consisting of xylated soybean oil and chlorinated paraffin
Injection molding material comprising a resin composition containing at least one plasticizer and having a molecular weight of 300 to 1500 of a polymer polyol which is a constituent component of the polyurethane (2).