JPH0657074A - Vinyl chloride resin composition for crosslinking - Google Patents

Abstract

PURPOSE:To provide a crosslinking vinyl chloride resin giving a vinyl chloride sheet for crosslinking having excellent appearance without causing the thermal deterioration in calendering while preventing the firm adhesion of the resin to the calender roll. CONSTITUTION:The vinyl chloride resin composition for crosslinking is produced by adding a compound having 2 or more acryloyl or methacryloyl groups in the molecule as a crosslinking agent to a vinyl chloride resin. The composition satisfies the formula (3.31X10<5>)R<-0.69=eta<=(4.68X10<5>)R<-0.69> (where 10<1=R<=10<2>) wherein eta (poise) is the viscosity of the composition at 180 deg.C and R (1/sec) is shearing rate. The composition does not cause thermal deterioration in calendering and the problem of the firm adhesion to the roll is remarkably improved. A vinyl chloride sheet for crosslinking having excellent appearance can be produced from the resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition for cross-linking by radiation such as electron beam, γ ray and ultraviolet ray, and more specifically to a sheet or film having a suitable appearance by calender molding. The present invention relates to a crosslinking vinyl chloride resin composition for molding.

[0002]

2. Description of the Related Art Conventionally, many proposals have been made for a vinyl chloride resin composition for cross-linking. For example, a composition using a radical generated by thermal cleavage of an organic peroxide in a cross-linking reaction, an electron beam, γ Compositions and the like using radicals generated by irradiation with radiation such as rays and ultraviolet rays are known.

In these resin compositions, it is practically necessary to add a cross-linking agent or a cross-linking aid in order to accelerate the cross-linking reaction, and when ultraviolet rays are used among the radiation, a photo-initiator is further added. It is necessary to add.

[0004]

However, in the vinyl chloride resin composition for cross-linking to which a cross-linking agent or the like is added, there are some drawbacks of the cross-linking agent in thermoplastic molding as compared with general vinyl chloride-based resin compositions. The problem of heat deterioration due to the low thermal stability of the vinyl chloride resin for cross-linking due to its low thermal stability, and the melting resin metal due to the lack of slipperiness between the vinyl chloride resin for cross-linking resin and the molds and roll surfaces in contact with it. There are problems such as strong adhesion to the mold or roll surface.

Particularly, the appearance of the vinyl chloride resin sheet for cross-linking and the film formed by calendering is affected by heat deterioration and the degree of adhesion to the calender rolls, so it is a great problem to prevent this heat deterioration and strong adhesion. Is.

[0006]

The present invention is intended to provide a vinyl chloride resin composition for cross-linking, which has improved strongly adhesion without being deteriorated by heat, and its gist is vinyl chloride resin. A vinyl chloride resin composition for cross-linking, wherein a compound having two or more acryloyl groups or methacryloyl groups in the molecule is added as a cross-linking agent.
The relationship between the viscosity η (poise) and the shear rate R (1 / sec) is (3.31 × 10 ⁵ ) × R ^−0.69 ≦ η ≦ (4.68 × 1)
This is a vinyl chloride resin composition for cross-linking in the range of 0 ⁵ ) R ^−0.69 (provided that 10 ¹ ≦ R ≦ 10 ² ).

The present invention will be described in more detail below. The vinyl chloride resin used in the present invention is a normal linear polymer, and one polymer having a polymerization degree can be used alone, or two or more polymers having a polymerization degree can be mixed and used. Further, those having a polymerization degree of 700 to 2000 can be preferably used.

The cross-linking agent is a compound having two or more acryloyl groups and methacryloyl groups in the molecule, and examples thereof include ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate and 1,6-hexanediol di (meth). ) Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexaacrylate, tris ((meth) acryloxyethyl) isocyanurate, epoxy acrylate, urethane acrylate and the like are used. These can be used alone or in combination of two or more. The addition amount is preferably 2 to 80 parts by weight with respect to 100 parts by weight of the vinyl chloride resin.

Other stabilizers, plasticizers, lubricants, processing aids,
As the pigment and the like, those conventionally used in general vinyl chloride resin blends can be used. However, when ultraviolet rays are used as the radiation, it is necessary to add a photoinitiator.

The temperature for calender molding is 170 to 180 ° C.
Is preferred, and the viscosity η (poise) of the vinyl chloride resin compound for crosslinking at 180 ° C. is (3.31 × 10 ⁵ ) R ^{−0.69
≤η≤} (4.68 × 10 ⁵ ) R ^-0.69 (however, 10 ^{1 ≤R}
≦ 10 ² ). When the temperature is lower than 170 ° C., unsatisfactory appearance is caused by unmelted components, and when the temperature is higher than 180 ° C., the melt viscosity of the composition is low and the appearance is poor due to strong adhesion with the roll.
Further, thermal crosslinking with a crosslinking agent causes poor appearance. The viscosity η and the shear rate R of the composition here are measured and measured by using “Flow Tester CFT-50A” manufactured by Shimadzu Corporation.

When η is smaller than (3.31 × 10 ⁵ ) R ^−0.69 , the melt viscosity of the sheet becomes low, causing poor appearance due to strong adhesion with the roll (4.68 × 10 ⁵ ).
When R ^{-0 .69} larger than a poor appearance due to uneven melting state of such unmelted fraction. Η of vinyl chloride resin compound
Can be changed by the structure of vinyl chloride resin, the degree of polymerization and the degree of polymerization distribution, the plasticization efficiency and ratio of vinyl chloride resin of liquid additives such as plasticizers and cross-linking agents, and the gelation efficiency of vinyl chloride resin of processing aids. It is a thing. In addition, R of 10 ¹ to 10
The range of ² substantially corresponds to the deformation speed in the pool (bank) of the molten resin between the rolls, which determines the appearance of the sheet and film during molding of the calendar.

[0012]

EXAMPLES The present invention will be described in more detail based on the following examples. Examples 1 to 4 The formulations shown in Table 1 were heated with stirring in a Henschel mixer until the temperature of the formulation reached 100 ° C, and cooled while stirring until the temperature of the formulation reached 60 ° C as a sample. Using.

This sample was kept horizontally and parallel between two metal heating rolls rotating in opposite directions with a speed difference, and a kneading was performed by forming a molten bank by shearing and heat transfer.
A sheet is formed on the roll surface, and 5 minutes after the sample is charged, the temperature of the sheet is measured and the sheet is peeled off from the roll. By observing the appearance of this sheet, a three-stage evaluation was made.
The test conditions were fixed as follows by changing only the type of sample. Amount of sample: 100 g Roll diameter: 20 cm Roll speed ratio: 10 m / min: 13 m / min Distance between rolls: 0.2 mm Width of sheet on roll surface: 20 cm (cut off the edge of the sheet when it exceeds 20 cm to form a bank Supply width of 20 cm
Keep on)

The three-stage evaluation criteria are as follows. XX: The sheet cannot be peeled off while being in close contact with the roll. X: The surface of the sheet has irregularities and the appearance is poor. ◯: The surface of the sheet is smooth and clearly visible, and the appearance is good. Sample temperature evaluation result including formulation and R = 1 at 180 ℃
Table 1 shows η at 0 ¹ and 10 ² .

Comparative Examples 1 to 4 The same compounding agents as in Examples 1 to 4 were used, and the tests were carried out and evaluated by the methods shown in Examples 1 to 4 while changing the degree of polymerization of vinyl chloride resin and the addition amount. Table 2 shows the formulation contents, sample temperature, evaluation results, and η at R = 10 ¹ and 10 ² . In Comparative Example 2, η is 165 ° C., and in Comparative Example 4, η is 185 ° C.

In each of Examples 1 to 4, (3.31 × 10
⁵ ) R ^−0.69 ≦ η ≦ (4.68 × 10 ⁵ ) R ^−0.69 (however, 10 ¹ ≦ R ≦ 10 ² ) is satisfied, and the appearance is good as shown in Table 1, while Comparative Example 1 18 for both 3 and
At 0 ° C., the above formula was not satisfied, and the appearance was poor as shown in Table 2. In addition, as shown in Table 2, Comparative Examples 2 and 4 in which η at a temperature other than 180 ° C. satisfies the above expression also have poor appearance, and it is understood that the correlation between the appearance and the range of viscosity η corresponds well.

[0017]

[Table 1]

[Table 2]

[0018]

As described above, according to the present invention, it is possible to obtain a vinyl chloride sheet for cross-linking which can greatly improve the strong adhesion and is not deteriorated by heat during calendering and has a good appearance.

Claims (1)

[Claims] 1. A vinyl chloride resin composition for cross-linking, comprising a vinyl chloride resin and a compound having two or more acryloyl groups or methacryloyl groups in the molecule as a cross-linking agent. The relationship between (poise) and shear rate R (1 / sec) is (3.31 × 10 ⁵ ) R
^-0.69 ≤ η ≤ (4.68 × 10 ⁵ ) R ^{-0.6 9} (however, 10
^A vinyl chloride resin composition for cross-linking in the range of ¹ ≦ R ≦ 10 ² ).