JPS60199044A - Flexible resin composition for use in tarpaulin - Google Patents

Abstract

PURPOSE:To provide a composition capable of giving tarpaulins of high productivity which is easy in calendering process and having outstanding high-frequency welder adhesiveness, comprising polyvinyl chloride resin, thermoplastic polyurethane resin and specific vinyl acetate-ethylene copolymer. CONSTITUTION:The objective resin composition comprising (A) 20-85wt% of polyvinyl chloride resin, (B) 5-75wt% of a thermoplastic polyurethane resin (pref. derived from diisocyanate and polyester polyol prepared from polybasic acid and polyhydric alcohol), and (C) 5-60wt% of a vinyl acetate-ethylene copolymer with a vinyl acetate content 85-40 (pref. 75-55)wt% and a Mooney viscosity (determined by the standard procedure, i.e. the JIS K-6300) >=8 (pref. 10-55).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tarpaulin that has excellent lamination processability and productivity with fibers and fabrics, is easy to calendar mold, and has excellent high-frequency welder adhesion, oil resistance, and heat resistance. The present invention relates to a soft resin composition for tarpaulins that can be used.

The #! using fibers, textiles, etc. as a base material! Tarpaulins, which are coated with rubber or synthetic resin on the front, back, or both sides, are widely used in clothing, industrial, and other fields. Synthetic rubber materials, soft polyvinyl chloride materials, ethylene-vinyl acetate materials, etc. are used as materials for this coating, but synthetic rubber materials must be vulcanized and crosslinked. The process is complicated, and high-frequency welder adhesion cannot be performed after vulcanization, and ethylene-vinyl acetate copolymer has low polarity, so it has poor adhesion processability with high-frequency welders, and it also has poor abrasion resistance and flexibility. It has its drawbacks. Under these circumstances, soft polyvinyl chloride resin materials are generally used most often in consideration of workability, mechanical properties, etc.

By the way, soft vinyl chloride resin materials contain a large amount of plasticizer in order to maintain cold resistance and flexibility, and may deteriorate due to volatilization or extraction of the plasticizer, or may deteriorate when used as a container. There are disadvantages such as migration of plasticizer into the contents.

Furthermore, there are known soft polyvinyl chloride resin materials that are softened without using a liquid plasticizer, such as those made by blending polyvinyl chloride with thermoplastic polyurethane.

However, a soft material made by blending polyvinyl chloride with thermoplastic polyurethane has a large amount of so-called "stagnation" at molding temperatures (high temperatures). The disadvantage is that it is difficult to remove thick sheets.
Furthermore, it has the disadvantage that the heat resistance of the calender roll is poor.

In particular, there is a need for a flexible polyvinyl chloride resin suitable for calendar molding, which has a faster production speed than extrusion molding, and can be easily laminated with textiles and base fabrics.

In view of these current circumstances, the inventors of the present invention have conducted extensive research and have found that a combination of polyvinyl chloride resin, thermoplastic polyurethane, and a specific vinyl acetate-ethylene copolymer has good seating properties and is easy to calendar molding. It has been found that a resin composition can be obtained that provides a tarpaulin that is easy to use and has excellent high-frequency welder adhesion.

That is, the present invention consists of 20 to 80% by weight of polyvinyl chloride resin, 5 to 75% by weight of thermoplastic polyurethane resin, and 5 to 60% by weight of vinyl acetate-ethylene copolymer,
A tarpaulin with excellent calender moldability, characterized in that the vinyl acetate content in the vinyl acetate-ethylene copolymer is 85 to 401!1%, and the Mooney viscosity measured according to JIS K-6300 is 8 or more. The present invention provides a soft resin composition for use.

The polyvinyl chloride resin used in the present invention is usually a vinyl chloride homopolymer, but monomers that can be copolymerized with vinyl chloride, such as ethylene, teropyrene, butene, vinyl acetate, and vinylidene chloride, are chlorinated at 20% by weight or less. Those copolymerized with vinyl may also be used.

The thermoplastic polyurethane resin used in the present invention is preferably one obtained from a polyester polyol obtained from a polybasic acid and a polyhydric alcohol, and a diisocyanate.

Examples of such polybasic acids include phthalic acid, adipic acid, and sepathic acid, and examples of polyhydric alcohols include ethylene glycol, propylene glycol, and 1,4-butanediol. Further, examples of the diisocyanate include tolylene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and the like.

The vinyl acetate-ethylene copolymer used in the present invention has a vinyl acetate content of 85 to 401if
% is used. Those with a vinyl acetate content of more than 85% by weight have problems such as poor compatibility with polyvinyl chloride resin, lack of flexibility, and poor cold resistance, while those with a vinyl acetate content of less than 401i% by weight The vinyl acetate-ethylene copolymer used in the present invention is undesirable because it has poor compatibility with polyvinyl chloride resins and thermoplastic polyurethane, causing deterioration of physical properties and processability. The vinyl acetate-ethylene copolymer used in the present invention has a Mooney viscosity of 8 or more, and when the viscosity is less than 8, calendering property is poor and calendering is more preferable. Mooney viscosity of 1O ~ 55 is used because it has disadvantages such as stickiness on the roll surface, poor temperature sensitivity of the obtained molded product, and poor dispersibility of vinyl acetate-ethylene copolymer. preferable.

The mixing proportions of the polyvinyl chloride resin, thermoplastic polyurethane resin, and vinyl acetate-ethylene copolymer used in the present invention are 20 to 85% by weight, 5 to 75% by weight, and 5 to 60% by weight, respectively. It is difficult to perform calender molding process if it is off, and sufficient mechanical properties etc. cannot be obtained.More preferably, polyvinyl chloride resin (A), thermoplastic polyurethane (B) and vinyl acetate-ethylene copolymer ( C) is 25-70%, 5-60% and 5-45% by weight, respectively, and (
The ratio of the total amount of (B) and (C) to A) is To
+30 to 20 j 80.

Conventional stabilizers, lubricants, plasticizers, colorants, ultraviolet absorbers, antioxidants, fillers, flame retardants, etc. can be added to the composition of the present invention.

The composition of the present invention can be used in conventional rubber and plastic mixers.
They are uniformly mixed or kneaded using a mixer. Kneading can be easily carried out using a mixing roll, a Banbury type mixer, a single-screw A or twin-screw extruder, etc. as a kneader.

The composition of the present invention has excellent calender moldability. The calendar molding method has a fast production speed, and is also suitable for fabrics, fibers,
It also has excellent lamination moldability with nonwoven fabrics and the like.

The compositions of the invention are particularly suitable for producing tarpaulins by calendering. The calendering conditions at that time vary depending on the composition ratio, but are usually 120 to 195℃.
A wide temperature range is suitable.

However, when tarpaulins are manufactured using conventional polyvinyl chloride resin/thermoplastic polyurethane blends, they can only be molded at relatively low temperatures, and the bending during molding is large, making it difficult to obtain tarpaulins of uniform thickness. The disadvantage is that it is difficult to

The base material for the tarpaulin is selected depending on the purpose and use, but synthetic fibers such as nylon, polyester, acrylic, polypropylene, cotton, linen, natural fibers, or nonwoven fabrics thereof are used.

The composition of the present invention and the substrate are laminated by a conventional method, for example, by coating one or both sides of the substrate using an inverted L calender roll, three calender rolls, or the like.

The tarpaulin obtained using the composition of the present invention has particularly excellent high frequency welder adhesion. That is,
The high-frequency bonding conditions are wide and the bonding strength is high. Therefore, the tarpaulin obtained by the composition of the present invention is widely used for clothing, agriculture, industrial materials, leisure, etc., and especially for flexible containers, tents, etc. It is useful for

Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Examples 1 to 3] and [Comparative Examples 1 to 4] The compositions shown in Table 1 were mixed uniformly with two wire crossing rolls at 165°C for 7 minutes to form a sheet, and then pressed at 165°C for 5 minutes. By molding, test pieces of 1fi thickness and 2fi thickness were obtained.

The tensile strength of the test piece was determined according to J■S K-6723, 10
0% modella, elongation, and low temperature embrittlement temperature were measured.

In addition, welder adhesion, roll processability, heat resistance, polystyrene transferability, and abrasion resistance were also measured. The results are shown in Table-1.

Regarding welder adhesion, the above 1-thickness test piece was
．． The two pieces were punched out to a width of 51 cm and a length of 15 cm, and the two sheets were superimposed and bonded at the same frequency of 8 x 5 sec using Takama Natsu Elder manufactured by Yamamoto High Frequency Research Institute, followed by a peeling speed of 20.
T-peel was performed at 0 .mu./min.

Regarding roll processability, 100 g of the compound was put into two kneading rolls set at a surface temperature of 180 ± 3°C, cross-cutting was performed with a roll gap of 0.3, and adhesion to the roll surface was observed for 10 minutes. The time required to take out the sheet was also measured.

Regarding heat resistance, test pieces obtained by press molding were tested at 120
It was expressed as the weight loss after being left in a gear set aging tester set at ℃ for 120 hours.

Regarding polystyrene transferability, a sample obtained by press molding and a polystyrene plate were stacked together and a load of 0.5 kr/- was applied at 80°C for 168 hours, and then the contact surface of the polystyrene plate was checked for discoloration, deformation, etc. Observed.

Regarding abrasion resistance, the amount of wear after testing using a taper set abrasion tester using a ring C3-17, 1 kg W 1 weight, and 1000 rotations is shown.

Further, a tarpaulin was obtained by calender-molding the composition shown in Table 1 on both sides of a polyester base fabric using an 8-inch inverted test calendar roll to a thickness of 0.3 m. The roll surface temperature in that gap is 1
The temperature was 60-170°C. The resulting tarpaulin is 2.5
Punch out the am medium X15dJK size, overlap the two sheets,
After adhesion was carried out using the same 1M frequency 8 x 5 sec using High Frequency Elder manufactured by Jyuju High Frequency Laboratory, the peeling speed was 20.
T-peel was performed at 0 m/min. The results are also shown in Table-1.

[Comparative Example 5] The composition shown in Table 1 was rolled at 125°C with two mixed wire rolls.
After uniformly kneading the mixture for a minute to form a sheet, the mixture was press-molded at 135° C. for 5 minutes to obtain test pieces with a thickness of 1 m and a thickness of 1 m.

In addition, a tarpaulin sheet having a thickness of 0.3 mm was obtained in the same manner. Hereinafter, sheet tests, tarpaulin preparations and tests were conducted in the same manner as in Examples 1 to 3 and Comparative Examples 1 to 4, and the results are shown in Table 1.

As is clear from Examples 1 to 3 and Comparative Examples 1 to 5, the composition according to the present invention has high welder adhesive strength, excellent roll formability, and also has good abrasion resistance and migration resistance. It is clear that it has excellent properties.

In addition, when a vinyl acetate-ethylene copolymer with a low Mooney viscosity is used, roll workability is poor, and similarly, roll workability is poor when a vinyl acetate-ethylene copolymer is not used. The vinyl chloride/DOP system has good welding workability and roll workability, but has poor abrasion resistance (also, transferability to polystyrene and heat loss are large).

In addition, in Table 1, vinyl acetate/ethylene copolymer (1): vinyl acetate content 60% by weight, Mooney viscosity 5G vinyl acetate/ethylene copolymer (2): vinyl acetate content 55
Vinyl acetate-ethylene copolymer with Mooney viscosity 15 in weight % Vinyl acetate/ethylene copolymer C3): Vinyl acetate content 2
Vinyl acetate-ethylene copolymer (4) with a melt index of 51% and a melt index of 3. Vinyl acetate/ethylene copolymer (4): a vinyl acetate content of 15% by weight and a melt index of 3! , 5 vinyl acetate-ethylene copolymer thermoplastic polyurethane: Pandex T-5265, polyester polyol polyurethane, manufactured by Dainippon Ink & Chemicals (1) Lubricant: Grec G7914, manufactured by the same company.

Agent: Patent Attorney Katsutoshi Takahashi

Claims (1)

[Claims] 20-85% by weight of polyvinyl chloride resin, 5-75% by weight of thermoplastic polyurethane resin and 5-60% by weight of vinyl acetate-ethylene copolymer! i amount%, and vinyl acetate-
The vinyl acetate content in the ethylene copolymer is 85 to 401
% and a Mooney viscosity of 8 or more as measured in accordance with JIS 11-6300. A soft resin composition for tarpaulin having excellent calender moldability.