JP3095077B2 - Vinyl chloride resin sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet made of a vinyl chloride resin having excellent properties of weather resistance, mechanical strength and compression set.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, vinyl chloride resins have been widely used for sheets and molded articles obtained by secondary processing of the sheets. However, weather resistance, mechanical strength and compression The distortion characteristics were poor and improvement was required. In particular, compression set is important because it relates to the shape retention of a molded article. Methods for improving this compression set include, for example, benzoyl peroxide, dicumyl peroxide, organic peroxides such as t-butyl peroxide, for example, 1,4-tetramethylenediamine,
Diamine compounds such as 1,6-hexamethylenediamine,
For example, a method of crosslinking a vinyl chloride resin with a sulfur-based compound such as sulfur, tetramethyl turum disulfide, and triazine dithiol, a method of crosslinking a component such as diallyl phthalate, a crosslinkable polyurethane or an epoxy resin, and a crosslinked vinyl chloride resin previously crosslinked at the time of polymerization Alternatively, a method of blending a crosslinked NBR or a crosslinked polyurethane having good compatibility with the vinyl chloride resin into the vinyl chloride resin, a method of using a vinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked body with diisocyanate or the like may be used. In these methods, when crosslinking the vinyl chloride resin, it is possible to easily obtain a composition having good compression set,
On the other hand, problems are: (1) poor thermal stability and easy coloring; (2) residual odor due to cross-linking agent residue; (3) a high degree of cross-linking requires 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.

When cross-linked vinyl chloride resin or cross-linked NBR is blended with vinyl chloride resin, (1) physical properties such as tensile strength and elongation are significantly reduced due to their dispersibility in vinyl chloride resin (2) hardness (3) Decrease in rebound resilience (4) Addition of a large amount deteriorates moldability (5) Poor weatherability due to butadiene component in cross-linked NBR.

Furthermore, in the method of using a vinyl 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, so that the improvement effect is small.

In recent years, a composite of a vinyl chloride resin and a polyurethane has attracted attention, and various methods have been proposed. For example, a method in which a polyurethane is dissolved in a vinyl chloride monomer (VCM) and a composite of the vinyl chloride resin and the polyurethane is obtained by polymerization of the VCM, a hydroxyl group-containing vinyl chloride resin is produced by polymerization of the VCM in the presence of a polyol, and A method obtained by a urethanation reaction, and further, a polyvinyl chloride resin, a polyol,
There is a method obtained by impregnating with an isocyanate, a catalyst or the like and reacting.

However, the composite of a vinyl chloride resin and a polyurethane obtained by these methods has poor rubber elasticity and is not suitable for applications requiring these properties. In such a method for producing a composite, when a urethane crosslinked product is produced using triisocyanate, the processability becomes poor. In addition, as a generally used composite method of a vinyl chloride resin and polyurethane, in a roll or Banbury mixer,
There is a method in which a vinyl chloride resin and a polyurethane elastomer having high elasticity are polymer-blended. Although the composite obtained by this method is excellent in rebound resilience, it is inferior in compression set, and thus improvement is desired.

Also, when used outdoors such as civil engineering sheets,
It is desired that weather resistance is good because of long-term exposure to sunlight. Vinyl chloride resin belongs to the class of resin with excellent weather resistance, but ordinary soft vinyl chloride resin using this is
Although it is excellent in weather resistance, it is inferior in compression set and is a problem. As a method for improving this, the method described above can be used.

Further, the sheet is often required to have excellent mechanical strength. For example, in the above-mentioned civil engineering sheet, there is a case where a large load is applied to use the sheet, so that the requirement is severe. As a method for improving this, for example, there is a method using a vinyl chloride resin having a high degree of polymerization.

However, a sheet that simultaneously satisfies weather resistance, mechanical strength and compression set, using vinyl chloride resin,
It has not been given yet.

[Means for Solving the Problems] In view of the above-described current situation, the present inventors have studied the components of the polyurethane that forms a crosslinked body, and as a result, have completed the present invention.

That is, the present invention has two or more hydroxyl groups and a molecular weight of 300 to 10,000 based on 100 parts by weight of the vinyl chloride resin.
0 to 10 to 170 parts by weight of a polymer polyol, a compound having three or more isocyanate groups and a plasticizer having an NCO / OH ratio corresponding to a molar ratio of hydroxyl groups of the polymer polyol to isocyanate groups of 0.3 to 1.3, and a plasticizer. Below, a vinyl chloride elastomer obtained by heating and melting and mixing,
The present invention relates to a sheet formed by molding a vinyl chloride-based elastomer in which the content of a tetrahydrofuran (THF) -insoluble content of the elastomer is 5 to 55% by weight.

 Hereinafter, the present invention will be described in detail.

The vinyl chloride resin used in the present invention may be one obtained by a commonly used polymerization method. For example, there are a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and an emulsion polymerization method.

In the present invention, the vinyl chloride resin refers to a homopolymer of vinyl chloride and a copolymerized vinyl chloride resin with a monomer copolymerizable with a vinyl chloride monomer.

The degree of polymerization of the vinyl chloride resin is 800 to 8,000, preferably 1,000 to 5,000.

Examples of the monomer copolymerizable with the vinyl chloride monomer include, for example, ethylene, propylene, butene, pentene-1,
Butadiene, styrene, α-methylstyrene, acrylonitrile, vinylidene chloride, vinylidene cyanide, alkyl vinyl ethers, carboxylic acid vinyl esters,
Aryl ethers, dialkylmaleic acids, fumaric esters, N-vinylpyrrolidone, vinylpyridine, vinylsilanes, alkyl acrylates,
Examples thereof include methacrylic acid alkyl esters.

Further, the vinyl chloride resin may be a graft polymer such as an ethylene-vinyl acetate-vinyl chloride graft polymer and a vinyl chloride-urethane copolymer. However, the vinyl chloride resin is not limited to these. A crosslinked vinyl chloride resin obtained by adding a divinyl compound such as divinylbenzene during the polymerization of these polymers is also used.

Cross-linked vinyl chloride resin is tetrahydrofuran (THF)
The insolubles are in the range of 0.1 to 25% by weight in weight percent and are used alone or in blends with uncrosslinked vinyl chloride resins.

The polymer polyol used in the present invention has two or more hydroxyl groups and has a molecular weight of 300 to 10,000, preferably 1,000 to 5,000. Such a polymer polyol has, for example, 5 to 5 repeating units obtained by ring-opening polymerization of an aliphatic dicarboxylic acid having 4 to 10 carbon atoms and an aliphatic glycol and / or epoxy group having 2 to 10 carbon atoms.
It can be obtained by condensation polymerization with the following glycol.

Incidentally, the molecular weight in the present invention indicates a number average molecular weight,
This can be measured by gel permeation chromatography (GPC) or the like.

2-10 carbon atoms used in the production of polymer polyols
The aliphatic glycol of, for example, 1,2-ethanediol, 1,2-propanediol, 1,4-butanediol,
Butenediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,10-decamethylenediol, 2,5-dimethyl-2,5-hexanediol, neopentyl glycol, 1,4- Cyclohexane dimethanol and the like.

On the other hand, compounds having an epoxy group include, for example, ethylene oxide, propylene oxide, tetrahydrofuran (TH
And cyclic ethers such as F). Those obtained by ring-opening polymerization of these glycols having a repeating unit of 5 or less,
It is suitably used as the glycol of the present invention. One or more of these are used.

4 to 10 carbon atoms used in the production of polymer polyols
Examples of the aliphatic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and the like, and one or more of these are used.

Such a polymer polyol is commercially available from Nippon Polyurethane Co., Ltd. under the trade name Nipporan.

The amount of polymer polyol added is 100 vinyl chloride resin.
It is 10 to 170 parts by weight based on parts by weight. If less than 10 parts by weight, rubber elasticity is not improved, and if it exceeds 170 parts by weight,
Processing becomes impossible.

The compound having three or more isocyanate groups used in the present invention includes, for example, 2,4- and 2,6-tolylene diisocyanate, m- and p-phenylene diisocyanate,
1-chlorophenylene-2,4-diisocyanate, 1,5-
Diisocyanates such as naphthalene diisocyanate, methylene bisphenylene-4,4'-diisocyanate, m- and p-xylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylene biscyclohexyl diisocyanate, isophorone diisocyanate, and trimethylhexamethylene diisocyanate Trimer, 1,6,11-undecane triisocyanate, lysine ester triisocyanate, 4-
Examples include triisocyanates such as isocyanatemethyl-1,8-octamethyldiisocyanate and 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.

However, the molar number of NCO groups of triisocyanate is preferably 0.25 or more based on the molar number of NCO groups of all isocyanates. If it is less than 0.25, sufficient performance cannot be exhibited due to insufficient crosslinking density.

Also, the NCO / OH ratio is in the range of 0.3 to 1.3. If it is less than 0.3, even if only triisocyanate is used as the isocyanate, sufficient performance cannot be exhibited due to insufficient crosslinking density. 1.
If it exceeds 3, processing is not possible.

There is no restriction on the use of the plasticizer in the present invention.
As the plasticizer that can be used in the present invention, for example,
Di-n-butyl phthalate, di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisooctyl phthalate, octyl decyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, di-isophthalate
Phthalic acid plasticizers such as 2-ethylhexyl, di-2-ethylhexyl adipate (DOA), di-n-adipate
Aliphatic ester plasticizers such as decyl, diisodecyl adipate, dibutyl sebacate, and di-2-ethylhexyl sebacate; trimellitic acid plasticizers such as trioctyl trimellitate and tridecyl trimellitate; and tetraoctyl pyromellitate Pyromellitic plasticizer,
Tributyl phosphate, tri-2-ethylhexyl phosphate,
Phosphate ester plasticizers such as 2-ethylhexyl diphenyl phosphate and tricresyl phosphate, epoxidized soybean oil,
Epoxy plasticizers such as epoxidized linseed oil, and high molecular weight plasticizers having an average molecular weight of 500 to 10,000 obtained by condensation polymerization of adipic acid or sebacic acid and glycol, and the like. used.

When the sheet material of the present invention is used outdoors, such as a civil engineering sheet, the weathering deterioration due to volatilization of the plasticizer becomes an important problem. Must be selected by

For example, a phthalate plasticizer in which the alcohol portion has 8 to 14 carbon atoms, a trimellitic acid plasticizer or a pyromellitic plasticizer in which the alcohol portion has 6 to 12 carbon atoms, or even an epoxy plasticizer. It is desired to use an agent and a polymeric plasticizer having an average molecular weight of 500 to 10,000 obtained by condensation polymerization of adipic acid or sebacic acid and glycol.

When preparing the vinyl chloride elastomer constituting the vinyl chloride resin sheet of the present invention, a catalyst may be used. Although the reaction proceeds without using a catalyst, it is preferable to use a catalyst because a uniform reaction proceeds. Such a catalyst may be a catalyst used in a general urethane reaction, and examples thereof include amine catalysts such as triethylamine, triethylenediamine, and N-methylmorpholine, tetramethyltin, tetraoctyltin, and dimethyldioctyltin. And tin-based catalysts such as triethyltin chloride, dibutyltin diacetate and dibutyltin dilaurate.

In the present invention, a stabilizer can be added to the vinyl chloride elastomer. Examples of the stabilizer include metal soap-based stabilizers such as lead stearate, calcium stearate, barium stearate, zinc stearate, and cadmium stearate, and epoxy-based stabilizers such as epoxidized soybean oil and epoxidized linseed oil. No.

Further, if necessary, an ultraviolet absorber, an antioxidant, an antioxidant, a processing aid, a filler, and the like which are usually used can also be blended. However, in the present invention, when a tin-based stabilizer is used, it serves as a catalyst for hydrolysis of the ester-based polymer polyol, so it is better to avoid using it.

The vinyl chloride elastomer constituting the vinyl chloride resin sheet of the present invention is used in a kneading machine capable of shearing and melting the resin, such as a roll forming machine, a twin-screw kneader, an extruder, and a Banbury mixer. More specifically, for example, taking a Banbury mixer as an example, first, at a casing temperature of 100 to 200 ° C., a vinyl chloride resin and an ultraviolet absorber, an antioxidant, an antioxidant, and a processing aid commonly used as necessary. And a filler are added and mixed. Next, the polyol, the plasticizer, the isocyanate, and the catalyst, which have been previously kept at 50 to 80 ° C., are weighed and mixed, and are charged from the inlet of the Banbury mixer. 100-200 while applying shearing force
C., and the mixture was further heated and mixed, and the vinyl chloride resin was melted and urethanized, and then taken out after 3 to 60 minutes. The thus obtained elastomer can be formed into a sheet by applying it to a roll forming machine.

It is necessary that the vinyl chloride elastomer constituting the vinyl chloride resin sheet of the present invention has a THF insoluble content of 5 to 55% by weight. When the insoluble content is less than 5% by weight,
If sufficient compression set is not given and exceeds 55% by weight,
Molding becomes difficult.

The method for measuring the THF-insoluble content is as follows. That is, a roll sheet having a thickness of 1.0 ± 0.1 mm is cut into 1.0 to 1.5 mm squares, and 1.0 g is weighed. Put this in a 300cc beaker and add 200
Stir for 2 hours with a stirrer in mlTHF. The sample swells with THF, but after filtering through a 300 mesh sieve,
This is crushed with a glass rod, etc.
Stir for 4 hours with a stirrer in HF. The solution is filtered through a filter paper that has been weighed in advance to separate insoluble components, the insoluble components and the filter paper are placed on a petri dish, dried in a 40 ° C. oven for 5 hours, and then weighed. The weight percentage of THF insolubles is determined from the weight of insolubles obtained by this method.

The sheet referred to in the present invention means a sheet obtained by molding with a roll molding machine, a calender molding machine, a T-die extrusion molding machine, and the like, for example, an automobile dashboard sheet, a home appliance surface heater sheet, and the like. Also included are cases obtained by subjecting this sheet to secondary processing using a compression molding machine, embossing rolls, and the like, and molded products such as leather and foam. Further, films for food, medical use, agricultural use, etc. also belong to this sheet. They are used for civil engineering, automotive, medical, agricultural, food, household, and other general purposes.

Further, the film referred to here is usually a film having a thickness of 0.2 mm or less, and a film having a thickness of more than 0.2 mm is called a sheet to be distinguished.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 A vinyl chloride resin (manufactured by Tosoh Corporation, trade name: Ryuron E-2800, average degree of polymerization) obtained by a suspension polymerization method in a Banbury mixer having an inner volume of 1700 cc and a casing temperature of 150 ° C.
2,800) as a stabilizer, barium stearate 1
2 g, zinc stearate 6 g, and 9 g of BP-331 (trade name, manufactured by Nissan Ferro-Organic Chemical Co., Ltd.) as an amine scavenger were charged and stirred at a constant rotation speed. Separately, polymer polyol (Nippon Polyurethane Co., Ltd.) which has been pre-heated to 70 ° C
Product name, Nipporan 4067, number average molecular weight 2,000) 240g
And trioctyl trimellitate (TOTM) 42 as a plasticizer
0 g, and mixed with a trimer of hexamethylene diisocyanate (Coronate E, trade name, manufactured by Nippon Polyurethane KK)
H) 39.8 g (NCO / OH ratio = 1) 0.03 g of dibutyltin dilaurate was charged as a catalyst, mixed for 1 minute, and then poured from the Banbury mixer inlet. The reaction and mixing time was 15 minutes.

After completion of the reaction, the obtained composite was rolled into a sheet by a roll forming machine, and then subjected to press molding, and each item was evaluated according to the evaluation method described below.

Evaluation method (1) Hardness Measured with a JISK6301 spring hardness tester (A type).

(2) Mechanical strength Tensile strength and elongation were measured according to JISK6301.

(3) Compression set Measured according to JISK6301.

(4) Weather resistance Sunshine Weatherometer (Suga Test Machine Co., Ltd.)
Manufactured), a tensile test after irradiation for 2,000 hours was performed, and the residual tensile strength and residual tensile elongation were measured.

 However, the tensile test conformed to JISK6301.

Weathering test conditions UV irradiation using carbon arc Black panel temperature: 63 ° C Water injection time: 18 min / 120 min Injection pressure: 0.8-1.3 kg / cm ² Test time: 2,000 hours The results are shown in Table 1.

Example 2 Adipic acid-based polyester plasticizer (ADEKA
Adekasizer PN-28 (trade name, manufactured by Argus Chemical Co., Ltd.)
Example 1 except that 420 g of 0, average molecular weight of 2,000) was used.
It was manufactured and evaluated in the same manner as described above.

 Table 1 shows the results.

Comparative Example 1 In a Henschel mixer, 1 kg of the vinyl chloride resin used in Example 1, 20 g of barium stearate, and zinc stearate were used.
10 g and 1.1 kg of TOTM were charged, heated and stirred, and dried up at 120 ° C. to obtain a vinyl chloride resin composition at 150 ° C.
For 5 minutes. Using this, evaluation was performed in the same manner as in Example 1.

 Table 1 shows the results.

Comparative Example 2 Adipic acid-based polyester plasticizer PN-280 as a plasticizer
Except for using 1.1 kg, all were manufactured and evaluated in the same manner as Comparative Example 1.

 Table 1 shows the results.

Comparative Example 3 In Example 2, the triisocyanate (Coronate E
H) instead of hexamethylene diisocyanate 19.
Except for using 8 g (NCO / OH ratio = 1), all were produced and evaluated in the same manner as in Example 2.

 Table 1 shows the results.

Comparative Example 4 In Comparative Example 2, a vinyl chloride resin (THF-soluble component) was polymerized by a usual suspension polymerization method using a crosslinking agent and the obtained resin had a THF-insoluble content of 0.7 wt%. Average polymerization degree 2,000) 1k
Except for using g, all were produced and evaluated in the same manner as in Comparative Example 2.

 Table 1 shows the results.

[Effects of the Invention] As is apparent from the above description, the vinyl chloride resin composite obtained by the present invention is rich in flexibility and easy in moldability. Further, it is characterized by low compression set and good weather resistance, and is useful for sheet materials.

Claims (1)

(57) [Claims] 1. A polymer polyol having two or more hydroxyl groups and having a molecular weight of 300 to 10,000, 10 to 170 parts by weight based on 100 parts by weight of a vinyl chloride resin, and a molar ratio of hydroxyl groups of the polymer polyol to isocyanate groups. Some NC
A vinyl chloride elastomer obtained by heat-melting and mixing a compound having three or more isocyanate groups corresponding to an O / OH ratio of 0.3 to 1.3 and a plasticizer under a shearing force, wherein the tetrahydrofuran-insoluble content of the elastomer is 5%. A vinyl chloride-based resin sheet formed by molding a vinyl chloride-based elastomer of up to 55% by weight.