JPH0867790A - Vinyl chloride resin sheet and its production - Google Patents

Abstract

PURPOSE: To improve the discoloration resistance, bleed-out resistance, light transmission properties, flame retardance, and light resistance of a vinyl chloride resin sheet by compounding a vinyl chloride resin, a specific antimony oxide, titanium oxide, and a plasticizer. CONSTITUTION: This vinyl chloride resin sheet having a light transmission of 40% or higher is obtd. by well mixing 100 pts.wt. vinyl chloride resin having a particle size of 50 mesh pass or lower, 3-39.5 pts.wt. antimony oxide having an average particle size of 0.2μm or lower as the flame retardant, 0.5-37 pts.wt. titanium oxide having an average particle size of 0.2μm or lower as the weather- resistant additive, and if necessary, 5 pts.wt or lower radical scavenger, kneading the resultant mixture while slowly adding 30-70 pts.wt. plasticizer to it, and forming it into a sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride sheet having excellent translucency and a method for producing the same.

More specifically, the present invention relates to a vinyl chloride sheet which is preferably used for industries such as warehouses or for amenity of outdoor sports and entertainment.

[0003]

2. Description of the Related Art Since vinyl chloride (hereinafter referred to as vinyl chloride) resin is usually hard and has low workability only with vinyl chloride resin, a softening agent called a plasticizer is used in an amount of 30 to 70 parts by weight per 100 parts by weight of vinyl chloride resin. Add to make a soft vinyl chloride resin.
Further, a modifier such as heat resistance, glossiness and antistatic property of the resin is added and mixed, and after kneading, a sheet is formed while softening with a calendar roll at 130 to 160 ° C. Such a soft PVC sheet has good moldability, is flexible, and is easy to use, and has been widely used from agricultural houses, industrial materials, building materials to household products. In recent years, in the industrial field such as warehouses and the amenity field such as outdoor sports facilities, the demand for highly translucent PVC sheets is increasing year by year in order to improve the lighting and expand the space.

However, the conventionally used transparent vinyl chloride sheet has a serious drawback that the flame retardancy is remarkably lowered because a modifier such as a plasticizer is added to the vinyl chloride resin, and its improvement is earnestly desired. It has been.

Therefore, in the conventional PVC sheet, various flame retardants have been added in addition to the above additives. Flame retardants are roughly classified into organic type and inorganic type, and as organic type, decabrom diphenyl ether and tetrabromobisphenol A are used.
And the like.

Although the organic flame retardant does not affect the translucency of the vinyl chloride resin, it has a problem of causing bleed-out or discoloration of the vinyl chloride resin by ultraviolet rays.

Aluminum hydroxide as an inorganic type,
Examples include magnesium hydroxide and antimony oxide. These materials have a problem that the translucency of the vinyl chloride resin is extremely lowered by adding a small amount.

Further, when used outdoors, good weather resistance is required.

For the purpose of improving the weather resistance, an organic or inorganic weather resistant agent is used, but if only the organic weather resistant agent is used, it does not affect the translucency of the vinyl chloride resin.
Since the effect is small, it is necessary to add a large amount of additive, and the flame retardancy is reduced. Therefore, it is preferable to use an inorganic weathering agent. However, the transparency of the vinyl chloride resin is impaired by the inorganic weathering agent, and when used in combination with the inorganic flame retardant, the transparency is extremely reduced.

In order to improve the light-transmitting property of the vinyl chloride sheet, it is necessary to improve the light-transmitting property of the vinyl chloride resin, but as described above, in the prior art, weather resistance, light-transmitting property and flame retardancy are required. No vinyl chloride sheet with satisfactory performance is disclosed for all of the above.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vinyl chloride sheet having all of flame retardancy, weather resistance and high translucency which cannot be obtained by the prior art.

[0012]

The vinyl chloride sheet of the present invention has the following constitution in order to achieve the above object. That is, a total of 5 parts by weight or more of antimony oxide having an average particle size of 0.2 μm or less and titanium oxide having an average particle size of 0.2 μm or less, and 30 parts by weight or more and 70 parts by weight of a plasticizer per 100 parts by weight of vinyl chloride resin. It is a vinyl chloride sheet which is made of a soft vinyl chloride resin that is contained in an amount of at most 40 parts and has a translucency of 40% or more.

The method for producing a vinyl chloride sheet of the present invention has the following constitution in order to achieve the above object.

That is, a vinyl chloride resin, antimony oxide having an average particle size of 0.2 μm or less, and an average particle size of 0.2
After mixing titanium oxide having a particle size of less than or equal to μm in the absence of a plasticizer, the plasticizer is gradually added and kneaded to mix and disperse the antimony oxide and the titanium oxide in a vinyl chloride resin, and then a sheet It is a method for producing a vinyl chloride sheet, which is characterized in that

The present invention will be described in detail below.

As the vinyl chloride resin used in the present invention, the pure powder containing no additive preferably has a fine particle size from the viewpoint of dispersion efficiency with the inorganic additive, and a grade classification screen 50 mesh pass product. A finer product is preferable, and a finer product than an 80 mesh pass product is more preferable.

The vinyl chloride resin originally contains a chlorine element and has flame retardancy. However, a vinyl chloride resin contains a plasticizer for improving the processability of the vinyl chloride sheet and an organic additive for improving other properties. It is added in a large amount.

In the present invention, the plasticizer is contained in an amount of 30 parts by weight or more and 70 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.

If the amount of the plasticizer is less than 30 parts by weight, the workability is low, and if it exceeds 70 parts by weight, the flame retardancy is lowered.

With these organic additives, the flame retardancy of vinyl chloride resin is significantly reduced. Therefore, in order to improve flame retardancy, decabromodiphenyl ether and tetrabromobisphenol A are well known in the prior art.
Such halogen-based organic flame retardants and inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, and antimony oxide are added and used.

The organic flame retardant has little effect on the light-transmitting property, but its effect is smaller than that of the inorganic flame retardant, so that it needs to be added in a large amount. Further, ultraviolet rays cause bleed-out or bleed-out in the vinyl chloride resin. There is a problem of causing discoloration.

On the other hand, an inorganic flame retardant generally has a large average particle size of several μm or more, and since it has a wavelength of visible light or more, it is diffusely reflected on the surface, and even if added in a small amount, it is transparent to a vinyl chloride resin. Is extremely low.

Further, there are organic and inorganic weathering agents added to improve the weatherability of the vinyl chloride resin. However, if only the organic weathering agent is used, the amount of the organic weathering agent added increases, and the flame retardancy of the vinyl chloride resin decreases.

Like the inorganic flame retardant, the inorganic weather resistant agent generally has an average particle size larger than the wavelength of visible light and is diffusely reflected on the surface of the particle, resulting in a decrease in light transmittance.

In the present invention, considering the problems in adding an organic flame retardant and an organic weathering agent to a vinyl chloride resin,
An inorganic flame retardant and an inorganic weather resistant agent are used. However, since the inorganic flame retardant and the inorganic weather resistant agent reduce the light-transmitting property, it is desirable to select ones which are effective in a small amount.

From the above viewpoints, antimony oxide is preferred as the inorganic flame retardant, and titanium oxide is preferred as the inorganic weathering agent.

Examples of the antimony oxide include antimony trioxide (Sb ₂ O ₃ ), antimony tetraoxide (Sb ₂ O ₄ ) and antimony pentoxide (Sb ₂ O ₅ ), which are added alone or in combination. Is preferred.

In the present invention, the following means are used in order to improve translucency while using an inorganic flame retardant and a weather resistance agent.

In order to prevent irregular reflection on the surface of the particles and allow visible light to pass therethrough, it is important to make the inorganic flame retardant and weather resistant agent fine particles to make the particle diameter smaller than the wavelength of visible light. Therefore, the average particle size of antimony oxide and titanium oxide should be 0.2 μm or less,
μm or less is preferable. If the average particle size exceeds 0.2 μm, the number of particles having a particle size exceeding the visible light wavelength of 0.4 μm increases, and there is a problem that the transparency of the vinyl chloride resin decreases.

Commercially available antimony oxide and titanium oxide having an average particle diameter of 0.2 μm or less can be used.

In the present invention, the particle size of the inorganic particles is
It is important not only from the viewpoint of the transparency of the vinyl chloride sheet but also from the viewpoint of uniform dispersion of the inorganic particles in the vinyl chloride resin.

From the viewpoint of flame retardancy and weather resistance, these antimony oxides and titanium oxides are used as the vinyl chloride resin 1
5 parts by weight or more based on 00 parts by weight,
It is preferable to contain a total of 8 parts by weight or more. If the total amount is less than 5 parts by weight, there is a problem that flame retardancy and weather resistance are deteriorated. However, from the viewpoint of translucency, the total addition of antimony oxide and titanium oxide is preferably 40 parts by weight or less, and more preferably 30 parts by weight or less.

On the other hand, if the total amount is less than 5 parts by weight, there is a problem that flame retardancy and weather resistance are deteriorated. From the viewpoint of flame retardancy, antimony oxide is preferably 3 parts by weight or more and 39.5 parts by weight or less, more preferably 5 parts by weight or more and 35 parts by weight or less, based on 100 parts by weight of the vinyl chloride resin. It is more preferable to add 10 parts by weight or more and 30 parts by weight or less.

From the viewpoint of weather resistance, titanium oxide is
It is preferable to add 0.5 parts by weight or more and 37 parts by weight or less, and more preferably 1.0 parts by weight or more and 35 parts by weight or less.

According to the present invention, the light transmittance of the PVC sheet is improved from the conventional 20 to 30% to 40 to 80%.

However, since antimony oxide and titanium oxide are affected by ultraviolet rays to generate radicals in the vinyl chloride resin, plasticizer, etc., causing discoloration and deterioration, it is preferable to add a radical scavenger to the vinyl chloride resin. preferable.

The radical scavenger is not particularly limited, but a hindered amine light stabilizer (hereinafter referred to as H
ALS) is preferably used.

The amount of the radical scavenger added is preferably 5 parts by weight or less per 100 parts by weight of the vinyl chloride resin from the viewpoint of preventing bleed-out on the surface or interface of the vinyl chloride resin.

However, excessive addition causes a problem of bleeding out on the resin surface or the like. The organic modifier may be contained as long as the effects of the present invention are not lost.

Further, in order to improve the light-transmitting property, it is important to uniformly disperse the inorganic flame retardant and weatherproofing agent in the vinyl chloride resin.

According to the conventional method, even if the particles are finely divided, uniform dispersion cannot be achieved. Vinyl chloride resin powder, plasticizer with this fine particles of inorganic flame retardant at the same time by a normal method, in the method of kneading with a calender roller device can not be dispersed sufficiently uniformly due to the difference in the specific gravity of the particles, fine particles aggregate The particle size becomes large, and the translucency of the vinyl chloride resin decreases.

In the present invention, in a method of mixing an inorganic flame retardant and a weather resistance agent having an average particle diameter of 0.2 μm or less with a vinyl chloride resin, the vinyl chloride resin powder and the inorganic fine particles used in the present invention are plasticized. After mixing well without the agent,
The plasticizer is preferably added slowly and kneaded to disperse the inorganic fine particles.

The reason why no plasticizer is added during mixing is as follows.
This is because if there is a plasticizer component during mixing, it tends to agglomerate, making uniform dispersion difficult. For the mixing, a Henschel mixer, an Erich mixer, or the like is preferably used. For subsequent kneading with the plasticizer, a method of simply kneading with a calender roller device to form a sheet or providing a pressure kneader before sheet formation with a calender roller device is preferably adopted from the viewpoint of sufficient kneading. .

The light transmittance of the vinyl chloride sheet of the present invention is 40% or more.

When the light transmittance of the vinyl chloride sheet is less than 40%, the light-collecting property becomes insufficient. The light transmittance is preferably 50% or more, more preferably 60% or more.

Since the light transmittance is 40% or more, antimony oxide having an average particle size of 0.2 μm or less and titanium oxide having an average particle size of 0.2 μm or less are used in the present invention.

Next, the flame retardancy of the PVC sheet will be described.

When a small number of people use it at once such as a warehouse tent, the flame retardancy may be low, but it is used in public facilities such as sports centers and recreation facilities used by a large number of people. Sheets require high levels of flame retardancy. The sheet used for the latter purpose is required to have a flame retardancy of Class 2 or higher (class 1 or class 2) measured by JIS A 1322 according to the certification of the Membrane Materials Association.

The vinyl chloride sheet of the present invention has a high light-transmitting property and a high flame retardancy, so that it can be used in public facilities.

The vinyl chloride sheet in the present invention is not limited to the shape such as a film or sheet, and includes a coating or padding.

[0051]

EXAMPLES Examples and comparative examples in the present invention will be shown below.

The flame retardancy and translucency of the obtained sheet were measured by the following methods.

Flame retardancy: Measured by JIS A 1322 "45 ° C. Meckel burner method" and indicated by the determined flame retardancy series.

Translucency: Numerical value of translucency measured by "Direct reading haze computer device" manufactured by Suga Test Instruments Co., Ltd. according to JIS K 7105.

T = [T ₂ / T ₁ ] × 100 T: total transmittance (%) T ₁ : incident light amount T ₂ : transmitted light amount [Example 1] PVC resin As a basic compounding agent, a PVC resin (55 mesh pass powder) 100 parts by weight and Ba-Zn
3 parts by weight of a thermal stabilizer, 1.5 parts by weight of a benzotriazole organic weathering agent, 5 parts by weight of antimony trioxide having an average particle size of 0.15 μm and 1 part by weight of titanium oxide are put in a Henschel mixer at the same time, and a plasticizer is added. Mix for 15 minutes without. Thereafter, 50 parts by weight of a plasticizer dioctyl phthalate (hereinafter referred to as DOP) and 5 parts by weight of tricresyl phosphate (hereinafter referred to as TCP) are further gradually added to this basic compounding agent and mixed for 10 minutes. Further, a transparent PVC sheet was obtained while kneading with a calendar roller. The light transmittance of this vinyl chloride sheet was 64%. The vinyl chloride sheet of the present invention not only has a high light transmittance, but also has a second-class flame retardancy, and a practical highly transparent vinyl chloride sheet was obtained.

The results are shown in Table 1.

[0057]

[Table 1] [Examples 2 and 3] In place of the antimony trioxide of Example 1, 5 parts by weight of fine particles of antimony tetraoxide (Example 2) and antimony pentaoxide (Example 3) having an average particle size of 0.15 μm were blended. And mixed with a vinyl chloride resin by the mixing method according to the present invention,
After kneading, a vinyl chloride sheet was obtained in the same manner as in Example 1. In the case of antimony tetraoxide, the transparency of the PVC sheet is 6
The flame retardancy was 2nd grade at 1% (Example 2). Similarly, in the case of antimony pentaoxide, the light transmittance of the vinyl chloride sheet was 67% and the flame retardancy was second grade (Example 3).

The results are also shown in Table 1.

[Examples 4, 5 and 6] 5 parts by weight (Example 4) and 10 parts by weight of fine particles of antimony pentoxide having an average particle diameter of 0.05 μm were used in place of the antimony trioxide of Example 1. Example 5), using 15 parts by weight (Example 6),
Titanium oxide having an average particle size of 0.05 μm was used, and was mixed and kneaded with a vinyl chloride resin by the mixing method according to the present invention. A highly transparent PVC sheet was obtained. The light transmittances of the vinyl chloride sheets of Example 4, Example 5 and Example 6 were 78%, 70% and 68%, respectively, in the state where each thickness was 0.7 mm.

The flame retardancy of the obtained vinyl chloride sheets also passed the second grade.

The results are also shown in Table 1.

[Example 7] In Example 1, as the vinyl chloride resin, 90 mesh-passed vinyl chloride resin powder was used in place of the ordinary vinyl chloride resin, and antimony trioxide having an average particle diameter of 0.15 µm and average particles were used. Titanium oxide having a diameter of 0.15 μm was simultaneously placed in a Henschel mixer, and mixed and kneaded in the same manner as in Example 1 to obtain a vinyl chloride sheet. The light transmittance of the obtained vinyl chloride sheet was 70%.

The flame retardancy of the obtained sheet was grade 2.

The results are also shown in Table 1.

[Example 8] In order to improve the weather resistance of a vinyl chloride sheet with inorganic fine particles, the vinyl chloride resin basic compounding agent of Example 4 was added to the commercially available Asahi Denka Co., Ltd. "ADEKA STAB LA-52" as a radical scavenger. Was added to obtain a vinyl chloride sheet in the same manner as in Example 4. Using Suga Test Instruments Co., Ltd. Sunshine Weather O-meter, 20 at 63 ℃
When the light transmittance after 00 hours was examined, there was almost no difference in the values within variations and no discoloration was observed.

The results are also shown in Table 1.

Comparative Example 1 100 parts by weight of a vinyl chloride resin (30 mesh pass powder), 50 parts by weight of a plasticizer, 5 parts by weight of TCP, and Ba—Zn heat stabilizer 3 without adding antimony oxide and titanium oxide. 1 part by weight and 1.5 parts by weight of a benzotriazole-based organic weathering agent are used as a vinyl chloride resin basic compounding agent. These were simultaneously placed in a Henschel device, mixed for 10 minutes, and then kneaded by a calendar roll method to obtain a vinyl chloride sheet. The light transmittance of this PVC sheet is 0.7
It was 92% in mm. The obtained PVC sheet is
The flame retardancy was out of grade and the weather resistance was extremely poor.

The results are shown in Table 2.

[0069]

[Table 2] [Comparative Example 2] 3 parts by weight of ordinary antimony trioxide having an average particle diameter of 0.3 µm and 1 part by weight of titanium oxide having an average particle diameter of 0.3 µm were simultaneously added to the basic compounding agent for vinyl chloride resin of Comparative Example 1 and a Henschel device. The mixture was put in a container and mixed for 10 minutes, and then a vinyl chloride sheet was obtained by kneading with a calendar roll method. The light transmittance of this vinyl chloride sheet was as low as 31% when the thickness was 0.7 mm, and the flame retardancy was also out of the grade.

The results are also shown in Table 2.

[Comparative Example 3] In order to improve the flame retardancy of vinyl chloride, the vinyl chloride resin basic compounding agent of Comparative Example 1 had an average particle size of 0.
Comparative Example 2 with 6 parts by weight of 3 μm antimony trioxide added
A vinyl chloride sheet was produced in the same manner as in. The obtained PVC sheet has a flame retardancy of grade 3, but a light transmittance of 0.7.
In the state of mm, it was as low as 24%, and a practical PVC sheet could not be obtained. The results are also shown in Table 2.

[Comparative Examples 4 and 5] The fine particle antimony oxide and titanium oxide used in Examples 1 and 4 were mixed by a conventional method,
The test was carried out by the kneading method. Average particle size of Example 1 0.1
6 parts by weight of 5 μm antimony trioxide and 1 part by weight of titanium oxide, 6 parts by weight of antimony pentaoxide having an average particle size of 0.05 μm used in Example 4 and 1 part by weight of titanium oxide were mixed in the same manner as in Comparative Example 3. Then, kneading was performed to obtain a vinyl chloride sheet. However, the transmittance of this vinyl chloride sheet is 23% in the case of antimony trioxide (Comparative Example 4) and 29% in the case of antimony pentaoxide (Comparative Example 5), which is extremely low and a practical salt. It didn't become a bisheet.

The results of the comparative example are also shown in Table 2.

[0074]

INDUSTRIAL APPLICABILITY In the present invention, since an inorganic flame retardant and a weather resistant agent are used, it is possible to prevent discoloration and bleed-out of the resin, which is a problem when an organic additive is used. It is possible to obtain a vinyl chloride sheet excellent in all of translucency, flame retardancy, and weather resistance, which cannot be obtained by conventional techniques.

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[Procedure amendment]

[Submission date] September 11, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Change

[Correction content]

The vinyl chloride sheet of the present invention has a high light-transmitting property and a high flame retardancy of the second grade or higher (first or second grade), and can be used in public facilities.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Change

[Correction content]

Flame retardance: Measured by JIS A 1322 "45 ° Meckel burner method" and indicated by the judged flame retardancy series.

Claims (4)

[Claims] 1. A total of 5 parts by weight or more of antimony oxide having an average particle size of 0.2 μm or less and titanium oxide having an average particle size of 0.2 μm or less based on 100 parts by weight of vinyl chloride resin.
A vinyl chloride sheet comprising a soft vinyl chloride resin containing a plasticizer in an amount of 30 parts by weight or more and 70 parts by weight or less and having a light-transmitting property of 40% or more. 2. To 100 parts by weight of vinyl chloride resin,
The vinyl chloride sheet according to claim 1, wherein the radical scavenger is added in an amount of 5 parts by weight or less. 3. The vinyl chloride sheet according to claim 1, wherein the antimony oxide is fine particles of antimony tetraoxide and / or antimony pentaoxide. 4. An average particle size of 0.2 μm with vinyl chloride resin.
After mixing antimony oxide of m or less and titanium oxide having an average particle size of 0.2 μm or less in the absence of a plasticizer, the plasticizer is gradually added and kneaded to obtain the antimony oxide and the titanium oxide. A method for producing a vinyl chloride sheet, which comprises mixing and dispersing in a vinyl chloride resin and then forming into a sheet.