JPH07173386A - Oil-resistant material - Google Patents

Abstract

PURPOSE:To provide an oil-resistant vinyl chloride material and a non-migrating material provided with both fatigue characteristics and rubber elastic properties such as compression permanent set. CONSTITUTION:An oil-resistant material and a non-migrating material consists of a resin composition which comprises a vinyl chloride resin, a polyurethane, and a polyester high mol.wt. plasticizer and/or an epoxy polymer plasticizer, and shows a sea-island type phase-separated structure when observed with a transmission type electron microscope. The tensile elastic modulus of the polyurethane is >=7X10<6>dyne/cm<2> and <=8X10<7>dyne/cm<2> at 20-70 deg.C on the observation of the linear viscoelasticity. The polyurethane contains as a diol component a polymerpolyol that the chemical shift of (1700-1750cm<-1>) peak originated from the stretching vibration of a carbonyl group in the polymerpolyol on the IR light absorption measurement of the 95/5 (weight ratio) mixture of the polyvinyl chloride resin/the polymerpolyol is <-3cm<-1> based on the position of the original polymerpolyol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl chloride oil resistant material or a non-migratory material having good oil resistance, fatigue characteristics and rubber elastic properties such as compression set. It is used for hoses and tubes for transportation of lubricating oil, sealing packings, gaskets and boots.

[0002]

2. Description of the Related Art Conventionally, NBR has been used as an oil resistant rubber material.
It has been used around various oils, mainly (acrylonitrile-butadiene rubber). However, for example, materials for hoses and boots have bending fatigue characteristics in addition to oil resistance.
As a packing material, a material having compression set characteristics in addition to oil resistance is desired.

Generally, as a polyvinyl chloride-based thermoplastic elastomer using the blending method, a blend of a polyvinyl chloride resin and a partially crosslinked NBR (acrylonitrile-butadiene rubber) is commercially available. However, while the polyvinyl chloride-based thermoplastic elastomer blended with the partially cross-linked NBR is effective for modifying rubber elastic properties such as compression set, mechanical properties represented by tensile strength, tensile elongation at break, etc. Regarding the performance related to the fatigue characteristics represented by the repeated bending test, the partially crosslinked NBR in the blend acts as a structural defect, so
At present, there is a demand for an elastomer having a good fatigue property and a rubber elastic property together with oil resistance, since it tends to deteriorate with the amount of BR added. In fact, for example, an elastomer material used for various boots for automobiles is required to have durability under long-term repeated bending or vibration, and an elastomer material having excellent fatigue properties is desired.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vinyl chloride oil resistant material having good oil resistance and rubber elastic properties such as fatigue characteristics and compression set.

[0005]

The present inventors have completed the present invention as a result of intensive studies in view of the above-mentioned present situation. That is, the present invention provides a resin composition comprising a polyvinyl chloride resin (1), a specific polyurethane (2) and a specific high molecular weight plasticizer (3), which is of sea-island type observed by a transmission electron microscope. A phase-separated structure is observed, the size of the separated structure is 0.01 micron or more and 500 micron or less, and the tensile elastic modulus in the linear viscoelasticity measurement of polyurethane (2) is 9 × 10 in the range of 20 ° C. to 70 ° C.
⁶ dyne / cm ² or more and 8 × 10 ⁷ dyne / cm ² or less, 20 parts by weight or more and less than 180 parts by weight of polyurethane (2) per 100 parts by weight of polyvinyl chloride resin (1), and a high molecular weight plasticizer (3) 20 parts by weight or more 180
An oil resistant material and a non-migratory material comprising a resin composition containing less than 1 part by weight.

The details of the present invention will be described below.

The polyvinyl chloride resin (1) used in the present invention is one or more of vinyl chloride homopolymer resin, chlorinated vinyl chloride resin, and all monomers copolymerizable with vinyl chloride monomer. 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 monomer of Resins obtained by grafting functional groups, resins obtained by reacting these functional groups with a reactive compound and graft-bonded, and the like are single or a mixture of two or more of the above resins.

The degree of polymerization of the polyvinyl chloride resin (1) is not particularly limited, but it is 4 from the viewpoint of molding processability of the obtained material.
00 or more and 8000 or less, more preferably 500 or more and 50
00 or less, more preferably 800 or more and 4000 or less. Further, a polyvinyl chloride resin having an arbitrary molecular weight may be blended with the polyvinyl chloride resin having a polymerization degree in the above range.

The polyurethane (2) used in the present invention has a tensile elastic modulus in the range of 20 ° C. to 70 ° C. in the linear viscoelasticity measurement of 7 × 10 ⁶ dyne / cm ² or more and 8 × 10 ⁷ d.
yne / cm ² or less, more preferably 1 × 10 ⁷ dyne
/ Cm ² or more and 7 × 10 ⁷ dyne / cm ² or less are used, and the compression set of the material of the present invention is improved by using such polyurethane. Further, in order to further improve the compression set characteristics 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 JISK6301.
It is the value measured according to the measuring method of the compression set described in (1), the measurement temperature is 70 ° C., and the time for applying the strain is 22 hours. Further, it is more effective to use polyurethane having a network structure as the polyurethane from the viewpoint of improving the compression set of the material of the present invention. That is, tetrahydrofuran (TH
In a good solvent such as F), it is desirable that the THF soluble content is 10% or less of polyurethane. Such polyurethane is obtained by the reaction of a polymer polyol with a compound having three or more isocyanate groups, or by the reaction of a high molecular weight linear compound having an isocyanate group at the polymer end with a compound having three or more hydroxyl groups. It is desirable to obtain polyurethane according to the method in terms of cost performance.

Further, in order to improve the compression set of the material of the present invention, the ratio of the compression elastic modulus of the matrix phase to the compression elastic modulus of the dispersed phase at 70 ° C. is preferably 0.4 or more and 1.8 or less. .

As described above, the polymer polyol as a raw material of the polyurethane (2) for exhibiting compression set has two or more hydroxyl groups, and includes polyester polyol, polyether polyol, polycarbonate polyol and vinyl. Examples thereof include system polyols, diene system polyols, castor oil system polyols, silicone polyols, polyolefin system polyols and copolymers thereof. Among these polyols, it is particularly effective to use a polymer polyol, which is originally poor in compatibility with the vinyl chloride resin, as a raw material for improving fatigue properties. Examples of these polymer polyols include diethylene glycol, polymer polyols containing adipic acid as a main component and polymer polyols containing ethylene glycol, butanediol and adipic acid as a main component, and these are commercially available (the former is Asahi. ADEKA NEW ACE Y52-21 manufactured by Denka Kogyo Co., Ltd.
The latter is a product name of Sanyo Kasei Kogyo Co., Ltd., Sun Esther 24620, Nippon Polyurethane Co., Ltd., Nipporan 4042, etc.). When the diol component is composed of two kinds of ethylene glycol and butanediol, it is particularly preferable to use a polymer polyol whose composition is in a weight ratio of 3/7 to 7/3.

The compatibility between the vinyl chloride resin and the polymer polyol referred to here is determined by a spectroscopic method (infrared absorption (I
R) peak movement amount in measurement), scattering method (small angle X-ray scattering, correlation length and concentration fluctuation in light scattering measurement), dynamic viscoelasticity method (narrowness of loss tangent peak), etc. . Among them, it is the simplest to use the spectroscopic method, and the polymer polyol having a poor compatibility with the vinyl chloride resin is a polymer in the IR measurement of the sample composed of vinyl chloride resin / polymer polyol = 95/5 (weight ratio). It is defined as a polymer polyol in which the peak at 1700 to 1750 cm ⁻¹ derived from the carbonyl stretching vibration in the polyol shifts by less than −3 cm ^{−1 with} respect to the position of the original polymer polyol.

On the other hand, a polymer polyol having a good compatibility with a polyvinyl chloride resin is effective in improving the compression set, but is poor in improving the fatigue characteristics.

The molecular weight of these polymer polyols is not particularly limited, but those of 300 or more and 10000 or less, and those of 500 or more and 5000 or less are preferably used. It is also possible to control the isocyanate index (number of isocyanate groups / number of hydroxyl groups) of polyurethane (2) in the material of the present invention. The isocyanate index is preferably 0.6 or more and 1.2 or less. 0.
If it is less than 6, it is effective in improving the fatigue properties, but sufficient compression set may not be obtained, or a sticky feel may occur during molding. On the other hand, if it exceeds 1.2, the fatigue properties may be impaired or coloring such as yellowing may occur, which is not preferable in appearance.

The ratio of the polyvinyl chloride resin (1) to the polyurethane (2) used in the present invention is not particularly limited, but in order to improve the compression set characteristics of the obtained material, the polyvinyl chloride resin (1) ) Polyurethane (2) is used in an amount of 20 parts by weight or more, preferably 30 parts by weight or more, and more preferably 45 parts by weight or more with respect to 100 parts by weight. From the viewpoint of cost performance, the addition amount of the polyurethane (2) is preferably less than 900 parts by weight, more preferably 30 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin (1).
The amount is less than 0 parts by weight, more preferably less than 180 parts by weight.

The high molecular weight plasticizer (3) used in the present invention is preferably a polyester and / or epoxy high molecular weight plasticizer having a number average molecular weight of 1000 or more and capable of efficiently plasticizing a polyvinyl chloride resin. . As such a high molecular weight plasticizer (3), an adipic acid type,
Examples thereof include sebacic acid-based and phthalic acid-based polyester high molecular weight plasticizers and epoxy high molecular weight plasticizers. If the number average molecular weight of this plasticizer is less than 1000, sufficient oil resistance cannot be realized. Further, if necessary, in addition to the high molecular weight plasticizer (3), a phthalic acid-based plasticizer typified by di-2-ethylhexyl phthalate (DOP), a trimellitic acid-based plasticizer, a phosphoric acid ester-based A low molecular weight plasticizer such as a plasticizer can also be used in combination. However, in that case, the mixing ratio of the high molecular weight plasticizer and the low molecular weight plasticizer is preferably in the range of 10/0 to 5/5 by weight. That is, if the low molecular weight exceeds 50%, the oil resistance may be impaired.

The use of the high molecular weight plasticizer (3) makes this material excellent in non-migratory property. Normal,
The rubber molding is made of other material such as styrene material or A
When contacting with a molded product of a BS (acrylonitrile-butadiene-styrene copolymer) material, phenomena such as stickiness, surface roughening, and tackiness are often problems due to migration of plasticizer or low molecular weight compound, but this material The high molecular weight plasticizer (3) used in (1) has very little migration and is preferable as a non-migration material.

The material of the present invention includes inorganic fillers such as calcium carbonate and talc, which are usually added to polyvinyl chloride resins to the extent that their performance is not extremely deteriorated, and antimony trioxide and zinc borate. A flame retardant, a partially crosslinked polyvinyl chloride, a modifier such as partially crosslinked acrylonitrile-butadiene rubber (NBR), and a processing aid typified by an acrylic resin can be added as necessary. In addition, a hydrolysis-resistant inhibitor typified by carbodiimide, which is usually added to polyurethane, a chlorine-based agent, a nitrogen-based agent, an antifungal agent typified by silver-zeolite agent, 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 oil resistance of the other resins. In this case, a compatibilizing agent of the material of the present invention and another resin can be used together 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 the polyurethane (2) is finely crushed by freeze pulverization or the like and then blended with the polyvinyl chloride resin (1). In this case, the device used for blending is optional and rolls, Banbury mixers, extruders and the like can be mentioned. (B) A method in which the 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 high molecular weight plasticizer (3), a polymer polyol, and an isocyanate compound under shearing force. In particular, the use of the above method (C) is preferable because the material of the present invention has improved material strength characteristics represented by tensile strength.

Further, the material of the present invention is dyed with a dyeing agent such as osmumic acid, and is then subjected to a transmission electron microscope (TEM).
Has a sea-island type phase separation structure when observed at
In addition, the size of the polyurethane dispersed phase, which is the island portion, must be 0.01 micron or more and 500 microns or less. When the size of the dispersed phase exceeds this range, the formability of the material of the present invention is significantly deteriorated.

In order to improve the molding processability, the size of the dispersed phase is preferably 0.03 micron or more and 400 micron or less, more preferably 0.05 micron or more and 300 micron or less.

The material of the present invention can be molded by a molding method that can be used for ordinary thermoplastic resins such as extrusion molding, injection molding, calender molding, blow molding and press molding. The molded product thus obtained becomes a material excellent in oil resistance, fatigue properties, non-migration property and compression set, and can be used as a hose for transportation of fuel oil, lubricating oil, etc.
It can be used for tubes, packings for sealing, gaskets, boots and the like.

[0023]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Example 1 Ethylene glycol and 1,4 butanediol (4 /
6)) and polymer polyol obtained by condensation polymerization of adipic acid (Nipporan 40 manufactured by Nippon Polyurethane Industry Co., Ltd.)
42, 80 parts by weight of a number average molecular weight of 2000) and an isocyanurate modified product of hexamethylene diisocyanate (trifunctional isocyanate compound) (Nippon Polyurethane Co., Ltd.)
Product name, Coronate HX) 13.53 parts by weight (NCO
/ OH ratio = 0.85), and DBTDL as a catalyst
(Dibutyltin dilaurate) 100 PPM were mixed and left in an oven at 120 ° C. for 2 hours to prepare polyurethane. 0.5mm thick and 5m wide from this sample
A strip-shaped test piece having a length of m and a length of 25 mm was cut out and used as a sample for measuring dynamic viscoelasticity. Separately, polyurethane obtained separately 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 (Leuron E-2800, average degree of polymerization: 2750, manufactured by Tosoh Corporation) 100 parts by weight, barium stearate 2 parts as a stabilizer, zinc stearate 1 part, Amine scavenger (Nissan Ferro Organic Chemical Co., Ltd. trade name BP-331) 1.5
Parts, 100 parts by weight of high molecular weight plasticizer (Adeka Sizer PN-280 (molecular weight = 2000), manufactured by Asahi Denka Co., Ltd.)
The composition was obtained by kneading at 150 ° C. for 10 minutes using an inch roll. After the kneading was completed, the obtained composition was molded into each test molded body and evaluated.

Example 2 Polymer Polyol and Polymer Polymer Polyol Obtained by Condensation Polymerization of 1,4 Butanediol (5/5) and Adipic Acid as Ethylene Glycol as Isocyanate Compound (Sanester 2462 manufactured by Sanyo Kasei Co., Ltd.)
0) 79.52 parts by weight, hexamethylene diisocyanate trimer (Nippon Polyurethane Co., Ltd., trade name Coronate HX) 13.88 parts by weight (NCO / OH ratio = 0.8)
The same molding process and material test as in Example 1 were performed except that 5) was used.

Example 3 80 parts by weight of a polymer polyol (Adecanuweace Y52-21 manufactured by Asahi Denka Co., Ltd.) obtained by condensation polymerization of diethylene glycol and adipic acid as a polymer polyol and an isocyanate compound, and 3 parts of hexamethylene diisocyanate. Body (Nippon Polyurethane Co., Ltd.)
Product name Coronate HX) 13.0 parts by weight (NCO / O
The same molding process and material test as in Example 1 were performed except that the H ratio was 0.85).

Example 4 77.92 parts by weight of a polymer polyol (Nipporan 4010 manufactured by Nippon Polyurethane Co., Ltd.) as a polymer polyol and an isocyanate compound, and a trimer of hexamethylene diisocyanate (Coronate HX manufactured by Nippon Polyurethane Co., Ltd.) 15 .48 parts by weight (NCO / OH ratio =
The same molding process and material test as in Example 1 were carried out except that the composition was changed to 1.02).

Comparative Example 1 3 as polymer polyol and isocyanate compound
-80 parts by weight of a polymer polyol (Nipporan 4067 manufactured by Nippon Polyurethane Co., Ltd.) obtained by condensation polymerization of methyl-1,5-pentanediol and adipic acid, and a trimer of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd.) The same molding process and material test as in Example 1 were carried out except that 13.4 parts by weight of trade name Coronate HX (NCO / OH ratio = 0.85) was used.

Comparative Example 2 Ethylene-vinyl chloride copolymer (LURON E-280
0, manufactured by Tosoh Corporation, 100 parts by weight, partially crosslinked NBR
(Japan Synthetic Rubber Co., Ltd. PNC-38, acrylonitrile content = 40%) 93.4 parts by weight, high molecular weight plasticizer (Adeka Sizer PN-280 (molecular weight = 2000), Asahi Denka Co., Ltd.) 100 parts by weight Was kneaded with a roll kneading material for 10 minutes to obtain a composition, and the same evaluation as in Example 1 was performed.

The compositions obtained above were evaluated by the following methods. The results are shown in Table 1.

(Evaluation of oil resistance) According to JIS K6301, the weight change rate after immersion in No. 1 oil and No. 3 oil kept at 100 ° C. for 70 hours or more was measured.

(Evaluation of Fatigue Property) In accordance with JIS K6301, an initial crack of 2 mm was 22.5 due to repeated bending.
The number of bends required to grow to mm was measured at room temperature.

(Evaluation of compression set) JIS K6301
It was measured according to. (70 ° C., 22 hours) (Evaluation of migration property) A polystyrene molded body having a thickness of 2 mm and an ABS molded body were each loaded with the molded body material having a thickness of 2 mm obtained in Examples and Comparative Examples, and air was heated at 80 ° C. for 168 hours. The appearance of the surface was visually evaluated after being left in the bath oven.
The presence or absence of surface roughness and stickiness was evaluated by ○ and ×.

(Evaluation of Compatibility between Polyvinyl Chloride and Polymer Polyol) The peak migration amount in infrared absorption (IR) measurement was evaluated. That is, T of a mixture of polyvinyl chloride resin and polymer polyol, 95/5 (weight ratio)
Derived from carbonyl stretching vibration in the polymer polyol in IR measurement of a film sample obtained by casting from an HF solution (solution concentration 10 wt%) (1700-1)
The 750 cm ⁻¹ ) peak was evaluated by the amount by which the position of the original polymer polyol was shifted by the interaction with the polyvinyl chloride resin. The shift amount is larger as the polyol has better compatibility with polyvinyl chloride. The results are shown in Table 2.

(Measurement of Dynamic Viscoelasticity) A viscoelasticity measurement analyzer RSA which is a measuring device based on the non-resonance type forced vibration method.
II (Rheometrics Far East Co.) measuring frequency 10 Hz, measuring mode: pulling, 2
The tensile storage elastic modulus (E ′) at 3 ° C. was measured.
The results are shown in Table 2.

(Confirmation of phase structure) A sample is exposed to vapor of osmumic acid, stained, and finished into an ultra-thin section of 0.1 micron in an atmosphere of -100 ° C with an ultramicrotome. This is an electron microscope JEOL manufactured by JEOL Ltd.
It was observed at an acceleration voltage of 200 kV using JEM-2000FX. In this observation, the component of polyurethane dyed with osmumic acid is 0.1 micron (μm) to 1
Dispersed phase (island phase) with a size of 00 microns (μm)
It was confirmed that it was dispersed. The results are shown in Table 2.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

According to the present invention, an oil resistant material and a delinquent material having excellent oil resistance, fatigue characteristics and compression set can be obtained.

Claims (2)

[Claims] 1. A resin composition comprising a polyvinyl chloride resin (1), a polyurethane (2) according to item 1 and a high molecular weight plasticizer (3) according to item 2, which is observed by a transmission electron microscope. Sea-island type phase-separated structure is observed, the size of the separated structure is 0.01 micron or more and 500 micron or less, and the tensile elastic modulus in linear viscoelasticity measurement of polyurethane (2) is 20 ° C to 70 ° C. 7 × in the range of
It is 10 ⁶ dyne / cm ² or more and 8 × 10 ⁷ dyne / cm ² or less, and 20 parts by weight or more and less than 180 parts by weight of polyurethane (2) and a high molecular weight per 100 parts by weight of the polyvinyl chloride resin (1). An oil resistant material comprising a resin composition containing 20 parts by weight or more and less than 180 parts by weight of a plasticizer (3). (Item ¹ ) A peak (1700 to 1750 cm ⁻¹ ) derived from carbonyl stretching vibration in the polymer polyol in infrared absorption (IR) measurement of a mixture of polyvinyl chloride resin and polymer polyol, 95/5 (weight ratio) Chemical shift relative to the original polymer polyol position-
Polyurethane using a polymer polyol having a diol component of less than 3 cm ^-1 . (Item 2) A polyester high molecular weight plasticizer and / or an epoxy high molecular weight plasticizer having a number average molecular weight of 1000 or more. 2. A resin composition comprising a polyvinyl chloride resin (1), a polyurethane (2) according to item 1 and a high molecular weight plasticizer (3) according to item 2, which is observed by a transmission electron microscope. Sea-island type phase-separated structure is observed, the size of the separated structure is 0.01 micron or more and 500 micron or less, and the tensile elastic modulus in linear viscoelasticity measurement of polyurethane (2) is 20 ° C to 70 ° C. 7 × in the range of
It is 10 ⁶ dyne / cm ² or more and 8 × 10 ⁷ dyne / cm ² or less, and 20 parts by weight or more and less than 180 parts by weight of polyurethane (2) and a high molecular weight per 100 parts by weight of the polyvinyl chloride resin (1). A non-migratory material comprising a resin composition containing 20 parts by weight or more and less than 180 parts by weight of a plasticizer (3). (Item ¹ ) A peak (1700 to 1750 cm ⁻¹ ) derived from carbonyl stretching vibration in the polymer polyol in infrared absorption (IR) measurement of a mixture of polyvinyl chloride resin and polymer polyol, 95/5 (weight ratio) Chemical shift relative to the original polymer polyol position-
Polyurethane using a polymer polyol having a diol component of less than 3 cm ^-1 . (Item 2) A polyester high molecular weight plasticizer and / or an epoxy high molecular weight plasticizer having a number average molecular weight of 1000 or more.