JPH07188495A - Polyvinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition exhibiting thermal aging resistance without detriment to low permanent compression set by mixing a vinyl chloride polymer with polyurethane-forming components which form a crosslinked body and a specified hydrotalcite compound. CONSTITUTION:This composition is prepared by melt-mixing under shear and heat a vinyl chloride polymer (A) with a polymer polyol (B), an isocyanate compound (C) having at least three isocyanate groups and a hydrotalcite compound (D) treated with a perchlorate and having a release water amount of 2wt.% or below on equilibrium upon heating to 165 deg.C. An example of component B is a polyester polyol, examples of component C include a trimer of a diisocyanate, a triisocyanate and a polyfunctional isocyanate. The addition amount of component D is preferably 1-10 pts.wt. per 100 pts.wt. total of components B and C. The total weight of components B and C is usually 30-900 pts.wt. per 100 pts.wt. component A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl chloride resin composition having excellent compression set and heat aging resistance.

[0002]

2. Description of the Related Art Vinyl chloride polymers (hereinafter referred to as PVC) are used as thermoplastic resins having excellent workability and versatility, such as pipes, corrugated sheets, sashes and films, sheets,
Widely used industrially as leathers, wire coatings, hoses, and daily necessities.

Conventionally, as a method for improving the load-bearing deformability of PVC, that is, the compression set, organic peroxides such as benzoyl peroxide, dicumyl peroxide, t-butyl peroxide, and 1,4-tetramethylene are used. A method of crosslinking PVC using a diamine compound such as diamine or 1,6-hexamethylenediamine or a sulfur compound such as sulfur, tetramethylthiuram disulfide or triazinedithiol, a component using diallyl phthalate or epoxy resin Cross-linking method, or cross-linked PVC that was previously cross-linked during polymerization or cross-linked nitrile butadiene rubber having good compatibility with PVC (hereinafter referred to as cross-linked NBR
And the like) are blended with PVC, and a method in which PVC having a reactive group such as a hydroxyl group is used to form a crosslinked product with diisocyanate or the like.

In these methods, when PVC is crosslinked, it is possible to easily obtain a composition having a good compression set, but on the other hand, the problem is that it is poor in thermal stability and easily colored. There is a problem that the odor remains due to the residue.

When cross-linked PVC, NBR, etc. are blended with PVC, the physical properties such as tensile strength and elongation are remarkably lowered due to their dispersibility in PVC, and a large amount of plastic is used for adjusting hardness. There is a problem that a weathering resistance and heat aging resistance are poor due to a butadiene component in the crosslinked NBR, which requires an agent.

Further, P having a reactive group such as a hydroxyl group
The method of forming a crosslinked product by using VC such as diisocyanate is inferior in reactivity and therefore has little improvement effect.

Therefore, in recent years, attention has been paid to the composite of PVC and PU, and various methods have been proposed. For example (1) PV
A blend of C and thermoplastic PU, and (2) a graft polymer of PVC and thermoplastic PU are disclosed in JP-A-58-403.
No. 12, No. 58-42611, No. 58-37019 and the like, by suspension polymerization of a thermoplastic PU soluble in a vinyl chloride monomer (hereinafter referred to as VCM) and VCM. Grafted composition, (3) PV
A composition disclosed in Japanese Patent Publication No. 59-39464 for producing PU in C has been proposed. However, the PVC compositions obtained by these methods are inferior in rubber elasticity and are not suitable for applications requiring these properties.
When a urethane crosslinked body is formed using a polyfunctional isocyanate in a method for producing such a resin composition,
The resin composition has poor processability.

Further, a polymer blend of generally used PVC and polyurethane having a high elasticity is also known, but since this has a poor compression set, further improvement is desired.

Under such circumstances, a resin composition obtained by heating, melting and mixing PVC, a polymer polyol, an isocyanate compound and, if necessary, a plasticizer with a shearing force has been proposed. Although the composition thus obtained has a lower compression set than that of the conventional composition, there is an increasing need for a more excellent compression set, and improvement is desired.

When PVC is compounded with a polyol and an isocyanate compound, the physical properties of the composition are deteriorated and the composition is colored and cracked due to deterioration of PVC over time in order to further deteriorate the durability (heat aging) of PVC alone. And so on. This occurs because hydrogen chloride gas generated from PVC is coordinated with urethane to form a quaternary ammonium salt, which exhibits a catalytic action for promoting PVC decomposition, or an amine compound is present in the system. It is believed that this is due to acceleration of PVC decomposition. Conventionally, stearates and the like have been added as stabilizers for the purpose of preventing deterioration of PVC due to hydrogen chloride gas released from the PVC. As the stearate, barium stearate, zinc stearate, calcium stearate, etc. have been used. However, in the compounding system of PVC and polyurethane, which has been studied in order to improve the compression set, thermal deterioration occurs more than in the conventional case, and it is the current situation that this stabilizer alone cannot deal with it.

For these reasons, problems such as deterioration of physical properties and deterioration of appearance have arisen in the fields of automobiles, construction materials, and applications in which outdoor use is required for long-term durability, and improvements have been demanded.

[0012]

In view of the above situation, the present invention is PV which is excellent in compression set and is also excellent in heat aging resistance.
A C composition is provided.

[0013]

DISCLOSURE OF THE INVENTION As a result of intensive studies made by the present inventors in view of the above-mentioned current situation, a PU forming a crosslinked body is obtained.
By adding a hydrotalcite-based compound in addition to the above components, it was found that a PVC composition exhibiting heat aging resistance while maintaining an excellent compression set can be obtained and completed. That is, the present invention relates to a PVC (1), a polymer polyol (2), an isocyanate compound (3) having 3 or more isocyanate groups, and a hydrotalcite-based compound having an equilibrium release water content of 2% by weight or less at a temperature of 165 ° C or lower. P which is obtained by heating, melting and kneading (4) under shear stress
It is a VC composition. The present invention will be described in detail below.

The PVC (1) used in the present invention is a vinyl chloride-containing polymer, which is one of vinyl chloride homopolymer, chlorinated vinyl chloride polymer, and monomer copolymerizable with vinyl chloride monomer. Random copolymerization with one or more monomers,
Examples thereof include vinyl chloride copolymers obtained by graft copolymerization or block copolymerization, and one or more of the above polymers are used.

Examples of the monomer copolymerizable with the vinyl chloride monomer include ethylene, propylene, butene, pentene-1, butadiene, styrene, α-methylstyrene,
Acrylonitrile, vinylidene chloride, vinylidene cyanide, alkyl vinyl ethers, carboxylic acid vinyl esters, aryl ethers, dialkyl maleic acids, fumaric acid esters, N-vinyl pyrrolidone, vinyl pyridine, vinyl silanes, acrylic acid alkyl esters, methacryl Examples thereof include acid alkyl esters.

The above PVC (1) has a degree of polymerization of 400 to 10,000, preferably 500 to 50.
00 or less, more preferably 500 or more and 3000 or less are used.

Polymer polyol (2) used in the present invention
Is not particularly limited, and for example, 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. . The polyester polyols mentioned here include ether ester type polyester polyols obtained by condensation polymerization of diethylene glycol and adipic acid, for example, and polyfunctionalized by being modified with other functional groups. In addition, a polyfunctional polyol having three or more hydroxyl groups such as polyester polyol, polycarbonate polyol, and polycaprolactone polyol is also included.

The compound (3) having 3 or more isocyanate groups used in the present invention is, for example, 2,4- and 2,6.
-Tolylene diisocyanate, m- and p-phenylene diisocyanate, 1-chlorophenylene-2,4-diisocyanate, 1,5-naphthalene diisocyanate, methylenebisphenylene 4,4'-diisocyanate, m- and p-xylene diisocyanate , Hexamethylene diisocyanate, lysine diisocyanate, 4,
4'-methylenebiscyclohexyl diisocyanate,
Trimer of diisocyanate such as isophorone diisocyanate and trimethylhexamethylene diisocyanate,
Triisocyanates such as 1,6,11-undecane triisocyanate, lysine ester triisocyanate, 4-isocyanate methyl-1,8-octamethyldiisocyanate, and polyfunctional isocyanates such as polyphenylmethane polyisocyanate are mentioned. 1 type (s) or 2 or more types are used.

It is also possible to use the above diisocyanates together as the isocyanate compound (3). However, it is desirable that the number of moles of isocyanate groups of the triisocyanate compound relative to the number of moles of isocyanate groups of all the isocyanate compounds used is 0.25 or more, and if it is less than 0.25, sufficient performance cannot be exhibited due to insufficient crosslinking density. There is.

The molar ratio of isocyanate group / hydroxyl group in the above-mentioned polymer polyol (2) and isocyanate compound (3) is in the range of 0.3 to 1.3 when diol is used as the polymer polyol (2). It is preferable. If it is less than 0.3, sufficient performance may not be exhibited due to insufficient crosslink density even if only triisocyanate is used as the isocyanate compound (3).
If it exceeds 1.3, processing may not be possible.

The total blending amount of the polymer polyol (2) and the isocyanate compound (3) used in the present invention is P
More than 30 parts by weight per 100 parts by weight of VC (1) 900
The amount is not more than 30 parts by weight, preferably not less than 30 parts by weight and not more than 500 parts by weight, and more preferably not less than 30 parts by weight and not more than 300 parts by weight. When the amount is within this range, the compression set and processability of the composition obtained are improved.

Hydrotalcite-based compounds are known as substances that can be used as ordinary resin deterioration inhibitors. This compound is a naturally occurring inorganic substance,
It is an intercalation compound consisting of a hydrate of magnesium and aluminum and a carbonate thereof, and the amount of metal ion components and the ratio of water of crystallization to the total amount thereof vary to some extent depending on the production status and processing and production. Generally, in the formation of a layer of this substance, a hydroxyl group is present in the outermost layer, a metal ion is present in the inner layer, and a hydroxyl group is again present in the inner layer, and the carbon dioxide is further present in the inner layer so as to be sandwiched by the three-layer structure. It has a structure in which ions and water are present. In addition, it is common that water is coordinated to the outside due to its structure. In addition, there is one in which the metal ion of this hydrotalcite compound is replaced with another ion such as zinc. Incidentally, these hydrotalcite compounds are commercially available (for example, Alkamizer manufactured by Kyowa Chemical Industry Co., Ltd.), and hydrotalcite compounds obtained by treating the hydrotalcite with perchloric acid are also commercially available (for example, Nissan. Ferro Organic Chemical Co., Ltd. BP-331).

According to the studies by the present inventors, it has been found that when the hydrotalcite-based compound treated with perchloric acid is added to a composition comprising PVC, a polymer polyol and an isocyanate compound, the heat deterioration resistance of the composition is improved. Was issued. However, on the other hand, a defect that the compression set characteristic of the composition is deteriorated was also found. Therefore, as a result of further study,
The hydrotalcite-based compound treated with perchloric acid was structurally slightly different from the original intercalation compound structure, and it was found that the absorption and release of water was extremely remarkable because the layers were slightly wide. From this fact, the water existing in the normal hydrotalcite compound is rapidly released at a temperature of about 180 ° C or higher, but the perchloric acid treatment causes the water to be released more slowly from the low temperature side, and the released water is released. It was found that the compression set characteristics of the resin composition obtained from the above deteriorate. Therefore, an examination based on this finding revealed that by adding a hydrotalcite compound whose amount of water released at the time of heating equilibrium of 165 ° C. to 2% by weight or less, the conventional hydrochlorite just treated with perchloric acid was used. A PVC composition having further excellent compression set physical properties as compared with those containing talcite and having the same excellent heat deterioration resistance was obtained.

In the present invention, the compounding amount of the above-mentioned hydrotalcite compound (4) is the total amount of the above-mentioned polymer polyol (2) and isocyanate compound (3) is 1
It is preferable to mix 1 to 10 parts by weight with respect to 00 parts by weight.

Further, a plasticizer may be added to the composition of the present invention, and the plasticizer which can be used at this time is, for example, di-n-butyl phthalate or di-2-phthalate.
Ethylhexyl (hereinafter referred to as DOP), di-n phthalate
Phthalic acid-based plasticizers such as octyl, diisodecyl phthalate, diisooctyl phthalate, octyldecyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl isophthalate, di-2-ethylhexyl adipate, di-n-adipate Decyl, diisodecyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate, and other aliphatic ester plasticizers, trioctyl trimellitate, tridecyl trimellitate, and other pyromellitic plasticizers, tributyl phosphate, phosphorus Phosphate ester-based plasticizers such as tri-2-ethylhexyl acidate, 2-ethylhexyl diphenyl phosphate, tricresyl phosphate, epoxy-based plasticizers such as epoxy-based soybean oil, polyester-based polymer plasticizers, and the like. One kind or two or more kinds can be used.

Further, in obtaining the PVC composition of the present invention, the above-mentioned components (1) to (4) may be heated and melt mixed under shear stress with a general urethanization reaction catalyst, which is used at this time. Examples of the catalyst include amine-based catalysts such as triethylamine, triethylenediamine and N-methylmorpholine, tin-based catalysts such as tetramethyltin, tetraoctyltin, dimethyldioctyltin, triethyltin chloride, dibutyltin diacetate and dibutyltin dilaurate. Etc. can be mentioned.

Further, the PVC composition of the present invention may contain a stabilizer which is usually added to PVC to the extent that the performance thereof is not extremely deteriorated. Examples of the stabilizer include lead soap stearate, calcium stearate, barium stearate, zinc stearate, metal soap-based stabilizers such as cadmium stearate, epoxidized soybean oil, epoxidized linseed oil and other epoxy stabilizers, and phosphite. Examples include phytic stabilizers. If necessary, a lubricant, a coloring agent, an inorganic filler represented by calcium carbonate, talc, etc., a flame retardant represented by antimony trioxide or zinc borate, and a light resistance stabilizer such as an ultraviolet absorber are appropriately added. can do.

The PVC composition of the present invention comprises the above components (1) to (1).
(4) can be obtained by heating and melting and mixing under shearing force. The heating and mixing under the shearing stress can be performed by, for example, a kneading machine capable of heating and shearing and melting resin such as Banbury mixer, calender roll, and extrusion molding machine. Can be done in. More specifically, for example, in the case of a Banbury mixer, the above components (1) to (4) are charged into the apparatus at a casing temperature of 100 to 200 ° C., and other stabilizers and the like are added if necessary. The PVC composition of the present invention can be obtained by heating, melting and kneading for a certain period of time.

The PVC composition of the present invention is obtained by heating and melting and mixing the above components under a shearing force, and the THF insoluble content in this composition is preferably 5 to 55% by weight. This makes the resulting composition excellent in compression set and moldability.

The THF-insoluble matter is measured by the following method.

(Method for measuring THF insoluble content) The obtained resin composition was freeze-pulverized and accurately weighed (Xg), which was subjected to Soxhlet extraction with THF for 8 hours to obtain an extract, which was then dried to obtain an extract. The THF-soluble matter in the solution was accurately weighed (Yg), and determined by the following formula: THF-insoluble matter (wt%) = 100 (X−Y) / X.

The molding material of the present invention comprises the above-mentioned PVC resin composition of the present invention. This material is produced by an extrusion molding machine, an injection molding machine and a calender molding process which are usually used for thermoplastic resins. It is a material that can be molded. And molded products obtained by molding this molding material will be excellent in compression set and heat aging characteristics, and these molded products should be used for automobile parts, wire coating materials, electric parts, sheets, tubes, etc. It can be done.

[0033]

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

Example 1 Ethylene-obtained by the suspension polymerization method in a Banbury mixer having an internal volume of 1700 cc and a casing temperature of 150 ° C.
Vinyl chloride copolymer (Ryuron E-2 manufactured by Tosoh Corporation)
800) 100 parts by weight, DOP 100 parts by weight, stabilizer 1 barium stearate 1 part by weight, zinc stearate 0.5 parts by weight, tetraphenyl polypropylene glycol diphosphite (trade name LT manufactured by Akishima Chemical Co., Ltd.)
-1000H) 0.6 parts by weight, dried at a temperature of 165 [deg.] C., and adjusted the water content to 7000 ppm, hydrotalcite treated with perchloric acid (Nissan Ferro Organic Chemical Co., Ltd. grade BP-331) 1.5 parts by weight. , Polymer polyol (manufactured by Nippon Polyurethane, trade name Nipporan, grade 4067, number average molecular weight 2000) 80.0 parts by weight, and a trimer of hexamethylene diisocyanate (trade name Coronate HX manufactured by Nippon Polyurethane Co., Ltd.) 13.4 Parts by weight (NCO / OH ratio = 0.85) and 0.0078 parts of dibutyltin dilaurate as a catalyst were charged, stirred at a constant rotation speed, reacted and mixed for 20 minutes to obtain a resin composition.

After the reaction was completed, the resin composition obtained was treated with 170
After being rolled into a sheet by a roll forming machine at 0 ° C., a test piece was press-molded for compression set (JISK6301) test, and a compression set test was conducted, and a heat deterioration test was performed on the sheet obtained by the roll forming machine.

The methods of compression set test and heat deterioration test are shown below.

(Compression set measuring method) The obtained resin composition was hot pressed at 175 ° C. to have a thickness of 12.7 ± 0.1 mm.
Cylindrical test piece was prepared and the compression set was measured by JISK6.
According to No. 301, the measurement was performed at 70 ° C. after 22 hours. First, the thickness of the obtained composition press-molded product was accurately measured (X mm), and it was placed in a compression set measuring device of JIS K6301 and was taken out after 70 hours at 22 ° C.
The thickness was measured again (Ymm) and calculated from the following formula. However, the spacer used here had a thickness of 9.52 mm. Compression set (%) = (X−Y) × 100 / (X−9.5)
2) (Heat resistance deterioration test method) For the weather resistance test, a Labo Plastmill mixer (manufactured by Toyo Seiki Co., Ltd.) with a capacity of 60 cc was used as a simple small batch mixer usually used for analysis of melt-kneading behavior of resin. . The test conditions are a casing temperature of 180 ° C. and a rotation speed of 40 rpm / min. The amount of the sample charged was 50 g, and the test time was evaluated and evaluated as the heat deterioration behavior as the elapsed time after the sample was charged until the resin composition melt was blackened due to the deterioration of the appearance. The criterion is indicated by the blackening time. ◯: Elapsed time to blackening is 120 minutes or more Δ: Elapsed time to blackening is 90 minutes or less ×: Elapsed time to blackening is 60 minutes or less Table 1 shows the evaluation results.

Example 2 The composition rolled into a sheet in Example 1 was crushed by a sheet pelletizer and made into pellets. A single-screw extruder (Labo Plastomill 20 manufactured by Toyo Seiki Co., Ltd.) was used.
mm sheet-screw extruder).
The extrusion conditions were as follows. Extrusion molding conditions: Die shape: Thickness 1 mm, width 20 mm Extruder screw rotation speed: 50 rpm Cylinder temperature: Heater 1 from material supply side
(150 ° C.) Heater 2 (150 ° C.) Heater 3 (165 ° C.) Die 1 (170 ° C.) The product obtained by the above molding was subjected to a heat aging test by the following method.

(Heat-resistant aging test method) For the heat-resistant aging test, a gear aging tester (manufactured by Yasuda Seiki Co., Ltd., model 102-S)
HF-S) was used. Molded product has a thickness of 1 mm and a width of 2
The shape was 0 mm and the length was 30 mm, and this was installed on the rotary drum in the apparatus. The test temperature condition was 170 ° C., and the change with time of the molded product was evaluated while constantly rotating the rotary drum. The criterion is shown below depending on the blackening time. ◯: Elapsed time to blackening is 120 minutes or more Δ: Elapsed time to blackening is 90 minutes or less ×: Elapsed time to blackening is 60 minutes or less Table 1 shows the evaluation results.

COMPARATIVE EXAMPLE 1 A composition was obtained in the same manner as in Example 1 except that 1.5 parts by weight of hydrotalcite treated with perchloric acid, which had been dried and adjusted to have a water content of 5% by weight, was used. Strain and heat deterioration test were conducted. The results are shown in Table 1.

Comparative Example 2 A composition was obtained in the same manner as in Example 1 except that 1.5 parts by weight of hydrotalcite treated with perchloric acid was used as it was without drying, and its compression set and heat deterioration test were conducted. It was The results are shown in Table 1.

Comparative Example 3 A composition was prepared in the same manner as in Example 1 except that hydrotalcite treated with perchloric acid, which had been dried and had its water content adjusted, was not used, and its compression set and heat deterioration test were conducted. . The results are shown in Table 1.

[0043]

[Table 1]

[0044]

As is apparent from the above description, according to the present invention, a polyvinyl chloride resin composition having a further improved compression set and an excellent heat aging resistance can be obtained.

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Claims (3)

[Claims] 1. A vinyl chloride polymer (1), a polymer polyol (2), an isocyanate compound (3) having 3 or more isocyanate groups, and a water content of 2% by weight or less at the time of heating equilibrium at 165 ° C. A polyvinyl chloride resin composition obtained by heat-melting and mixing a perchloric acid-treated hydrotalcite compound (4) with a shear stress under a shear stress. 2. The hydrotalcite compound (4) is blended in an amount of 1 part by weight to 10 parts by weight with respect to 100 parts by weight of the total amount of the polymer polyol (2) and the isocyanate compound (3). The polyvinyl chloride resin composition described. 3. A molding material comprising the polyvinyl chloride resin composition according to claim 1 or 2.