KR20130049052A - Polyvinyl acetal film having improved uv resistance and preparation method thereof - Google Patents

Abstract

PURPOSE: A polyvinylacetal film is provided to have improved penetration resistance, impact resistance, and yellowing resistance by limiting a temperature range of a melt extrusion process to be within a specific range. CONSTITUTION: A polyvinylacetal film comprises a polyvinylacetal resin and a plasticizer. The material is manufactured by melt extruding the material at 100-175 °C and has a yellowing index according to ASTM E313. A manufacturing method of the polyvinyl acetal film comprises a step of mixing a plasticizer and additives into a polyvinyl acetal resin; and a step of placing the raw material resin in an extruder with a twin or single screw, melt extruding at temperature of 100-175 °C, and cooling the melt extruded material to obtain a final film.

Description

Polyvinyl acetal film excellent in yellowing resistance and its manufacturing method {POLYVINYL ACETAL FILM HAVING IMPROVED UV RESISTANCE AND PREPARATION METHOD THEREOF}

The present invention relates to a polyvinyl acetal film that can be used as a bonding film for automobiles, buildings, solar modules, and the like and a method of manufacturing the same.

Plasticized polyvinyl acetals (particularly polyvinylbutyral) are commonly used in the production of polymer sheets for use as interlayers in light transmitting laminates such as laminated glass (safety glass) or polymer laminates. Laminated glass typically refers to a transparent laminate comprising a polyvinylbutyral sheet sandwiched between two sheets of glass. Laminated glass is mainly used to provide transparent barriers in buildings and automotive openings. Its main function is to minimize the damage or injury to an object or person in the transparent barrier by absorbing energy, such as caused by a blow from the object, without allowing penetration through the opening. Additives for sheet manufacture generally include adhesion modifiers to improve the adhesion of the sheet to the glass, as a result of which an appropriate level of adhesion can be maintained and adequate energy absorption to impact while preventing glass from breaking. To provide. In addition, the interlayer sheet can be improved to impart additional beneficial effects to the laminated glass, such as attenuating acoustic noise, reducing UV and / or IR light transmission, or improving the aesthetics of the window opening. In particular, as a film used for glass of automobiles, buildings, solar modules, and the like, a film having improved blocking resistance has been developed.

Korean Laid-Open Patent Publication No. 2006-0056282 discloses a polymer sheet comprising a bifunctional surface modifier of polyethylene-block-polyethylene glycol polymer, which improves the blocking resistance of the sheet while maintaining optical transparency and glass adhesion. .

However, such a conventional polyvinyl acetal film may be easily decomposed by heat than ethylene vinyl acetate (EVA) film to cause yellowing, and due to the cleavage of the main chain by pyrolysis, the penetration resistance and impact resistance may be deteriorated.

Accordingly, development of a new polyvinyl acetal film having improved yellowing resistance and impact resistance is required.

Korean Laid-Open Patent Publication No. 2006-0056282

Accordingly, it is an object of the present invention to provide a polyvinyl acetal film excellent in yellowing resistance, impact resistance and the like in various external environments and a method of manufacturing the same.

According to the above object, the present invention comprises a polyvinyl acetal resin and a plasticizer, a polyvinyl acetal film having a melt-extrusion temperature of 100 to 175 ℃, yellow index (YI) according to ASTM E313 is 3.0 or less To provide.

According to another object of the present invention, (a) preparing a raw material resin by mixing a plasticizer and an additive to a polyvinyl acetal resin; And (b) putting the raw material resin into an extruder having twin or single scoops, melt extruding at a temperature of 100 to 175 ° C., and then cooling the raw material resin to obtain a final film.

Moreover, this invention provides the laminated glass bonded by the said polyvinyl acetal film.

The polyvinyl acetal film of the present invention as described above, by limiting the temperature range in the melt extrusion process to a specific range, it is possible to improve the penetration resistance, impact resistance, and yellowing resistance, glass such as auto, building, solar module, etc. It can be used as a bonding film for to exhibit excellent performance.

The film of the present invention comprises a plasticizer and an additive in a polyvinyl acetal resin, and is characterized in that the film is produced at a melt extrusion temperature of 100 to 175 ° C. Preferably the film is produced using an extruder having a twin or single screw.

The polyvinyl acetal resin may be a polyvinyl butyral resin, a polyvinyl formal resin, a glutaraldehyde-crosslinked polyvinyl butyral resin, or a blend resin thereof, wherein the polyvinyl butyral resin has a glass and refractive index. It is most preferable because it is similar and transparent and well bonded with glass. In addition, the weight average molecular weight of the polyvinyl acetal resin is preferably 50,000 to 250,000.

Such polyvinyl acetal resin is preferably contained in 30 to 90% by weight, more preferably 50 to 75% by weight based on the total weight of the film is good in impact resistance, mechanical properties, heat resistance when bonding with glass.

In addition, as the plasticizer Triethyleneglycol bis 2-ethylhexanoate (3G8), tetraethyleneglycol diheptanoate (4G7), triethyleneglycol bis 2-ethylbutyrate (3GH), triethyleneglycol bis 2-heptanoate (3G7), dibu And a plasticizer selected from oxyethoxyethyl adipate (DBEA), dibutyl sebacate (DBS), bis 2-hexyl adipate (DHA), and mixtures thereof. Such plasticizer is preferably contained in each resin layer at 9 to 69% by weight, more preferably 24.5 to 49.5% by weight based on the total weight of the film, in view of heat resistance, mechanical properties, impact resistance, and water resistance of the film.

The film of the present invention may contain additives selected from antioxidants, UV stabilizers, UV absorbers, glass adhesion modifiers and mixtures thereof.

Specifically, as the antioxidant, Irganox, butylhydroxytoluene (BHT) and the like of Basf may be used; As the UV stabilizer, Tinuvin or the like of Basf may be used; As the UV absorber, Chemisorb 12, Chemisorb 79, Chemisorb 74, Chemisorb 102, Tinuvin328, Tinuvin329, Tinuvin 326, etc., manufactured by Chemiproplasty, can be used; As the glass adhesion modifier, Mg, K, Na, epoxy-modified Si oil, or a mixture thereof may be used.

Such additives are preferably contained in an amount of 0.01 to 1.0% by weight, more preferably 0.2 to 0.5% by weight based on the weight of the resin layer in view of thermal safety, light resistance, and glass bonding strength.

Polyvinyl acetal film of the present invention preferably has a total thickness of 0.2 to 2.0 mm, there is an advantage to improve the impact resistance and penetration resistance within the above range.

It is preferable that both of the surface roughness Rz of the film of this invention are 20 micrometers or more, for example, it may be 20-70 micrometers. When the surface roughness is in the above range, a blocking phenomenon may occur when the film is loaded during the process, and deairing may be more effectively performed during the glass bonding process.

Such polyvinyl acetal film of the present invention,

(a) preparing a raw material resin by mixing a plasticizer and optionally an additive with a polyvinyl acetal resin; And

(b) the raw material resin having twin or single screw It can be prepared, including the step of putting in an extruder melt-extruded and cooled at a temperature of 100 to 175 ℃ to obtain a final film.

In the above production method, polyvinyl acetal resin, plasticizer, additives, etc., which are the material components, may be mixed in each component and content range to have the composition of the film of the present invention as described above.

As described above, the melt extrusion temperature of the film of the present invention needs to be in the range of 100 to 175 ° C., but if the melt extrusion temperature is less than 100 ° C., the viscosity of the polyvinyl acetal resin is too high and the flowability is low so that the shear stress (shear ), The frictional heat generation can be increased, and if it exceeds 175 ℃, the thermal bond can break the acetate bond having the lowest binding energy, and then the acetal bond breaks, resulting in thermal decomposition, yellowing phenomenon and viscosity decrease due to decomposition. And the workability is reduced due to the volatilization of the plasticizer. More preferably, the extrusion temperature is 120 to 160 ℃.

In addition, the smaller the difference between the extrusion temperature and the resin temperature is preferable, for example, it is preferable to adjust the difference between the resin temperature and the extrusion temperature is 0 to 20 ℃, more preferably 0 to 9 ℃. At this time, the extrusion temperature means the setting temperature of the extruder, the resin temperature means the temperature that the resin is directly received by the heat generated by the pressure pushed by the screw. When the difference between the extrusion temperature and the resin temperature is as small as the above range, it means that no heat is generated, thereby reducing yellowing of the film. When the difference between the extrusion temperature and the resin temperature exceeds the above range, the frictional heat is high, which may cause thermal decomposition, which is not preferable.

The extruder used to produce the film according to the present invention is a twin screw or single screw type extruder, preferably a plasticizer capable of sufficiently mixing a polyacetal resin and a plasticizer, and having migrated to the surface; It is an extruder that can vent up pyrolysis products.

In addition, as the number of kneaders provided in the extruder increases, the friction heat of the raw material resin increases, and thermal decomposition may accelerate due to the frictional heat, which may result in yellowing. Preferably, it is preferable to use an extruder having one to three kneaders.

Said step (b) after the surface pattern treatment on both sides of the film may further include the step of so that both the surface roughness (Rz) of both sides to 20㎛ or more, for example, RZ Matrit surface processed to 20㎛ or more It can be carried out through a process of heating and surface compression using, in this case it can be improved blocking resistance and degassing.

As described above, the polyvinyl acetal film of the present invention extrudes a raw material resin containing polyvinyl acetal resin at a temperature in the range of 100 to 175 ° C. to prevent thermal decomposition, thereby increasing penetration resistance and impact resistance, and suppressing yellowing of the film. Can be.

Preferably, when the yellow index (YI) is measured according to ASTM E313 for the film of the present invention, it may be 3.0 or less, more preferably 2.5 or less, especially in a condition of 400-1100 nm. Preferably 1.5 or less. Since it is possible to increase the visible light region transmittance within the above range, there is an advantage that the solar efficiency is increased when the solar module is applied, and the impact resistance, mechanical properties, transparency, visibility, and quality are increased when bonding with glass.

In addition, the penetration height of the penetration resistance test of the polyvinyl acetal film laminated glass according to the KS L 2007 standard may have a characteristic of more than 4m. When it is in the said range, it is preferable because it is excellent in shock absorption, glass protection, and safety.

In addition, when the 4T glass-polyvinyl acetal film-4T glass laminate was manufactured according to the falling ball impact test procedure of the laminated glass according to KS L 2004, and the steel sheet weighing 1.20 kg was dropped with a high height, Since the glass may be broken or not open, it is preferable in terms of glass scattering prevention, shock absorption, and safety.

In addition, as evaluation of the pummel bonding strength, the amount of glass remaining on the film after producing a 2.1T glass-polyvinyl acetal film-2.1T glass laminate, cooling to -18 ° C, and successively using a hammer was 30 to 30%. If it is less than 30%, the bonding strength between the glass and the film is poor, and if it is more than 90%, the bonding strength is too high and the film may be torn, which is not preferable.

Accordingly, the film of the present invention can exhibit excellent performance when used as a bonding film for glass, in particular for the automotive, building, or a bonding film for the glass of the solar module.

The present invention thus provides a laminated glass bonded by the polyvinyl acetal film. The laminated glass according to the present invention may have a laminated structure of glass - polyvinyl acetal film-glass, and the thickness range of the glass used is preferably 1.0 to 5.0 T.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

The components used in the following examples and comparative examples are as follows:

-Polyvinyl butyral (PVB) resin: 70 mol% butylation degree, number average molecular weight 140,000, Tg 72 ℃, MH, Hefei TNJ, China

-Triethylene glycol bis 2-ethylenehexanoate: purity of at least 97.0%, WVC3800, Celanese, Germany

-Chemisorb 12: Benzophenone series, Chemipro Chemicals, Japan

-Chemisorb 79: Benzotriazole series, Chemiprosseong Co., Japan

Irganox: hindered phenolic, Basf, Germany

Butylhydroxytoluene (BHT): Product name: Lanxess, Vulkanox, Germany

Mg, K, and Na: Mg acetate, K acetate, Na acetate, OCI Corporation, Korea

-Epoxy modified Si oil: KCC Silicone, Korea

Example 1

Based on 100% by weight of the raw material resin, 69.79% by weight of polyvinyl butyral (PVB) resin, 30% by weight of triethylene glycol bis 2-ethylenehexanoate as a plasticizer, 0.1% by weight of Chemisorb 79 as a UV absorber, Irganox 0.1 as an antioxidant A raw material resin composition was prepared by mixing the wt% and 0.01 wt% of Mg + K + Na as a glass adhesion modifier.

The raw resin composition was melt extruded through a twin screw extruder equipped with one kneader at a melting temperature of 150 ° C., and cooled on a casting roll at 20 ° C. to obtain a film. At this time, by connecting a sensor that can detect the resin temperature to the melt conduit of the extruder and measuring the resin temperature, it was adjusted so that the difference between the resin temperature and the extrusion temperature is not large.

The film cooled by the casting roll was heat-pressed at a temperature of 100 ° C. in a matrol having a Rz 70 μm roughness to finally complete a film having a surface roughness of Rz 35 μm and a total thickness of 0.76 mm.

Example 2 and Comparative Examples 1 and 2

Using the resin composition of the composition as shown in Table 1 as a raw material resin composition, except that the manufacturing process was carried out as shown in Table 1, the same procedure as in Example 1 was carried out to finally complete the film.

Test Example

The physical properties of the polyvinyl acetal films prepared in Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1 below.

* Y.I (Yellow Index) Evaluation

Yellow index of the polyvinyl acetal film was measured according to ASTM E313. Specifically, the laminated film of the release film-polyvinyl acetal film-release film (silicone coated PET) was laminated in a laminator at 150 ° C. for 15 minutes by heating and pressing to prepare a specimen, and after removing the release film from the specimen, the Hunter It measured on the conditions of 400-1100 nm using the measuring instrument of Lab.

* Drop height

Based on KS L 2007, the penetration resistance of the glass by which the polyvinyl acetal film was laminated was evaluated. Specifically, the laminated structure of 2.1T glass-polyvinyl acetal film-2.1T glass of 300mm x 300mm was laminated in a laminator at 150 ° C. for 15 minutes by heating and pressing to prepare a specimen, and then, a steel ball of 2.26 kg was prepared. The height (MBH) through which the specimen penetrated was measured.

Glass evaluation

Based on KS L 2004, the presence or absence of the glass which the polyvinyl acetal film was laminated was evaluated. Specifically, the laminated structure of 4T glass-polyvinyl acetal film-4T glass of 610mm x 610mm was laminated in a laminator at 150 ° C. for 15 minutes by heating and pressing to prepare a specimen, and then raised the steel ball of 1.20kg. Falling on the specimen as it went, it was checked whether the impacted specimen was broken and the glass was shattered or opened.

* Fummel Bonding Force Evaluation

The adhesive force between the polyvinyl acetal film and the glass was evaluated through the evaluation of the pummel bonding force. Specifically, a laminated structure of 2.1T glass-polyvinyl acetal film-2.1T glass of 300 mm x 300 mm was laminated in a laminator at a temperature of 150 ° C. for 15 minutes by heating and pressing to prepare a specimen, and the specimen was −18 ° C. After cooling and consecutively using a hammer, the amount of glass remaining in the polyvinyl acetal film was measured. The case where no glass remained in the film was set to 0, and in the case where all glass remained in the film, 10 As a result, values from 0 to 10 were assigned.

(The numbers in parentheses in the table above represent the weight percentage of each component.)

As shown in the table, the polyvinyl acetal film of the embodiment according to the present invention exhibited excellent performance compared to the polyvinyl acetal film of the comparative example according to the prior art in yellowing resistance, penetration resistance, impact resistance and the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It is to be understood that the invention may be practiced within the scope of the appended claims.

Claims (11)

Polyvinyl acetal resin and plasticizer,
As a film produced by melt extrusion at 100 to 175 ℃,
A polyvinyl acetal film having a yellow index (YI) of 3.0 or less according to ASTM E313.
The method of claim 1,
The melt extrusion temperature is characterized in that 120 to 160 ℃, polyvinyl acetal film.
The method of claim 1,
Wherein said polyvinyl acetal resin is polyvinyl butyral resin, polyvinyl formal resin, glutaraldehyde-crosslinked polyvinyl butyral resin, or blend resin thereof.
The method of claim 1,
The surface roughness (Rz) of both surfaces of the said polyvinyl acetal film is 20 micrometers or more, The polyvinyl acetal film characterized by the above-mentioned.
The method of claim 1,
The plasticizer is triethylene glycol bis 2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), triethylene glycol bis 2-ethylbutyrate (3GH), triethylene glycol bis 2-heptanoate ( 3G7), dibutoxyethoxyethyl adipate (DBEA), dibutyl sebacate (DBS), bis 2-hexyl adipate (DHA), and mixtures thereof, added in an amount of 9 to 69% by weight Polyvinyl acetal film, characterized in that.
The method of claim 1,
The polyvinyl acetal film, polyvinyl acetal, characterized in that it contains an additive selected from antioxidants, UV stabilizers, UV absorbers, glass adhesion control agents and mixtures thereof in an amount of 0.01 to 1% by weight based on the weight of the film. film.
The method of claim 1,
The polyvinyl acetal film is a polyvinyl acetal film, characterized in that the penetration height is greater than 4m as a result of the penetration resistance test of polyvinyl acetal film laminated glass according to KS L 2007 standard.
(a) preparing a raw material resin by mixing a plasticizer and an additive with a polyvinyl acetal resin; And
(b) the raw material resin having twin or single screw It is put into an extruder and melt-extruded at a temperature of 100 to 175 ℃ and cooled to obtain a final film, the method of producing a polyvinyl acetal film of claim 1.
9. The method of claim 8,
Method for producing a polyvinyl acetal film, characterized in that using the extruder having one to three kneader (kneader) as the extruder.
9. The method of claim 8,
After the step (b), the surface pattern treatment on both sides of the film further comprises the step of so that both the surface roughness (Rz) of both sides to 20㎛ or more, a method of producing a polyvinyl acetal film.
The laminated glass bonded by the polyvinyl acetal film of any one of Claims 1-7.