JP4960898B2 - Interlayer film for laminated glass and laminated glass - Google Patents

Description

The present invention relates to an interlayer film for laminated glass having excellent light resistance, capable of controlling the color tone to light yellow while reducing ultraviolet transmittance while maintaining high visible light transmittance, and laminated glass. .

Laminated glass is widely used as a window glass for vehicles such as automobiles, aircrafts, buildings, and the like because it is safe because it does not scatter glass fragments even if it is damaged by an external impact. Examples of the laminated glass include laminated glass in which an interlayer film for laminated glass made of polyvinyl acetal such as polyvinyl butyral plasticized with a plasticizer is interposed between at least a pair of glasses.

Such a laminated glass is safe because it does not scatter glass fragments even if it is damaged by an external impact. When used as a window glass for vehicles such as automobiles, aircraft, buildings, etc., laminated glass is used in an environment where ultraviolet rays contained in sunlight are irradiated. The conventional interlayer film for laminated glass contains an ultraviolet absorber for shielding ultraviolet rays, but shields only ultraviolet rays having a wavelength range of 380 nm or less, and thus sufficiently shields ultraviolet rays having a wavelength range exceeding 380 nm. I couldn't.

As a method for solving such a problem, for example, Patent Document 1 discloses an intermediate for laminated glass containing a synthetic resin, an ultraviolet absorber, and a yellow dye capable of absorbing light in the wavelength region of 380 to 450 nm. A membrane is disclosed. The interlayer film for laminated glass disclosed in Patent Document 1 is said to be capable of shielding light in a wavelength region of 450 nm or less while maintaining the daylighting property.
However, in Patent Document 1, no method for uniformly dispersing the yellow dye in the interlayer film for laminated glass has been studied, and an interlayer film for laminated glass having high visible light transmittance could not be obtained. Furthermore, the interlayer film for laminated glass disclosed in Patent Document 1 has a problem in that it cannot sufficiently shield ultraviolet rays having a wavelength range exceeding 380 nm. Furthermore, the interlayer film for laminated glass having a strong yellowish color is not preferable because it is associated with deterioration.

Patent Document 2 discloses a laminated glass in which an interlayer film for laminated glass is interposed between two glasses, and the interlayer film for laminated glass is a laminated glass made of a synthetic resin material to which an organic light absorber is added. Has been.
However, the organic light absorbent disclosed in Patent Document 2 has a problem that it is easily deteriorated by irradiation with ultraviolet rays. Therefore, when the interlayer film for laminated glass of Patent Document 2 is used in an environment irradiated with ultraviolet rays, there is a problem in that the effect of shielding light rays having a wavelength range exceeding 380 nm decreases with time. .
JP 2000-300149 A JP 2007-290923 A

In view of the above situation, the present invention can reduce the ultraviolet transmittance while maintaining a high visible light transmittance, can control the color tone to light yellow, and is an interlayer film for laminated glass having excellent light resistance, And it aims at providing a laminated glass.

The present invention is an interlayer film for laminated glass containing a thermoplastic resin, a plasticizer, and a light absorber having an anthraquinone structure having a thiophenyl group, wherein the light absorber is contained in 100 parts by weight of the thermoplastic resin. It is an interlayer film for laminated glass having a content of 0.003 to 0.007 parts by weight.
The present invention is described in detail below.

As a result of intensive studies, the inventors have reduced the ultraviolet transmittance while maintaining a high visible light transmittance by containing a specific light absorber in a specific ratio in the interlayer film for laminated glass. The inventors have found that it is possible to control the color tone to light yellow and that it has excellent light resistance, and have completed the present invention.

The interlayer film for laminated glass of the present invention contains a thermoplastic resin.
The thermoplastic resin is not particularly limited, and examples thereof include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic copolymer resin, polyurethane resin, polyurethane resin containing sulfur element, and polyvinyl alcohol resin. . Especially, since the intermediate film for laminated glasses which exhibits the adhesiveness outstanding with respect to glass will be obtained when used together with a plasticizer, polyvinyl acetal resin is used suitably.

The polyvinyl acetal resin is not particularly limited as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol with an aldehyde, but a polyvinyl butyral resin is preferable. Moreover, you may use together 2 or more types of polyvinyl acetal resin as needed.
The preferable lower limit of the degree of acetalization of the polyvinyl acetal resin is 40 mol%, the preferable upper limit is 85 mol%, the more preferable lower limit is 60 mol%, and the more preferable upper limit is 75 mol%.

When a polyvinyl butyral resin is used as the polyvinyl acetal resin, the preferred lower limit of the amount of hydroxyl groups is 15 mol%, and the preferred upper limit is 35 mol%.
If the amount of hydroxyl group is less than 15 mol%, the adhesion between the interlayer film for laminated glass and the glass may be lowered, or the penetration resistance of the resulting laminated glass may be lowered. When the amount of hydroxyl groups exceeds 35 mol%, the resulting interlayer film for laminated glass may become hard.

The polyvinyl acetal resin can be prepared by acetalizing polyvinyl alcohol with an aldehyde.
The polyvinyl alcohol is usually obtained by saponifying polyvinyl acetate, and polyvinyl alcohol having a saponification degree of 80 to 99.8 mol% is generally used.
Moreover, the preferable minimum of the polymerization degree of the said polyvinyl alcohol is 200, and a preferable upper limit is 3000. When the polymerization degree is less than 200, the penetration resistance of the resulting laminated glass may be lowered. When the said polymerization degree exceeds 3000, shaping | molding of the intermediate film for laminated glasses may become difficult. The more preferable lower limit of the degree of polymerization is 500, and the more preferable upper limit is 2000.

Although it does not specifically limit as said aldehyde, Generally, a C1-C10 aldehyde is used suitably. The aldehyde having 1 to 10 carbon atoms is not particularly limited. For example, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonyl Examples include aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, benzaldehyde and the like. Of these, n-butyraldehyde, n-hexylaldehyde, and n-valeraldehyde are preferable, and n-butyraldehyde is more preferable.
These aldehydes may be used alone or in combination of two or more.

The interlayer film for laminated glass of the present invention contains a plasticizer.
The plasticizer is not particularly limited, and examples thereof include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, phosphorus compounds such as organic phosphoric acid plasticizers, and organic phosphorous acid plasticizers. An acid plasticizer etc. are mentioned, It is preferable that the said plasticizer is a liquid plasticizer.
The monobasic organic acid ester is not particularly limited. For example, glycols such as triethylene glycol, tetraethylene glycol, and tripropylene glycol, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, and n-octyl Glycol ester compound obtained by reaction with monobasic organic acid such as acid, 2-ethylhexylic acid, pelargonic acid (n-nonyl acid), decyl acid or the like and tetraethylene glycol, tripropylene glycol and the above organic acid An ester compound etc. are mentioned. Among them, triethylene glycol dicaproic acid ester, triethylene glycol di-2-ethylbutyric acid ester, triethylene glycol di-n-octylic acid ester, triethylene glycol di-2-ethylhexyl acid ester and the like triethylene glycol dialkyl acid Esters are preferred.

Although the said polybasic organic acid ester is not specifically limited, For example, ester compound of polybasic organic acid, such as adipic acid, sebacic acid, azelaic acid, and the alcohol which has a C4-C8 linear or branched structure Is mentioned. Of these, dibutyl sebacic acid ester, dioctyl azelaic acid ester, dibutyl carbitol adipic acid ester and the like are preferable.

The organic ester plasticizer is not particularly limited, and triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n- Octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethyl butyrate, 1,3-propylene glycol di 2-ethyl butyrate, 1,4-propylene glycol di-2-ethyl butyrate, 1,4-butylene glycol di-2-ethyl butyrate, 1,2-butylene glycol di-2-ethylene butyrate, diethylene Glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethyl Butyrate, diethylene glycol dicapryate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol bis-2-ethylbutyrate, triethylene Glycol di-2-ethylhexanoate, triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, dihexyl adipate, dioctyl adipate, hexyl adipate Hexyl, mixtures of adipic acid heptyl and adipic acid nonyl, diisononyl adipate, Hepuchirunoniru adipic acid, dibutyl sebacate, oil-modified sebacic alkyds, mixtures of phosphate esters and adipic acid esters, adipic acid esters, C ₄ -C ₉ alkyl C ₆ -C ₈ adipate such as mixed adipate prepared from alcohol and cyclic C ₄ -C ₁₀ alcohol, hexyl adipate and the like.

The organophosphate plasticizer is not particularly limited, and examples thereof include tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphate, and the like.

Among the above plasticizers, dihexyl adipate (DHA), triethylene glycol di-2-ethylhexanoate (3GO), tetraethylene glycol di-2-ethylhexanoate (4GO), triethylene glycol di-2- At least selected from the group consisting of ethyl butyrate (3GH), tetraethylene glycol di-2-ethylbutyrate (4GH), tetraethylene glycol diheptanoate (4G7) and triethylene glycol diheptanoate (3G7) One type can prevent a change with time in the adhesive force between the interlayer film for laminated glass and the glass by containing a metal salt of a carboxylic acid having 5 or 6 carbon atoms as an adhesive force adjusting agent.
Furthermore, since the above plasticizer hardly undergoes hydrolysis, triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH), tetraethylene glycol di-2- Ethyl hexanoate (4GO) and dihexyl adipate (DHA) are preferable, and triethylene glycol di-2-ethylhexanoate (3GO) is more preferable.

Although it does not specifically limit as content of the said plasticizer in the intermediate film for laminated glasses of this invention, A preferable minimum is 30 weight part with respect to 100 weight part of said thermoplastic resins, and a preferable upper limit is 70 weight part. When the content of the plasticizer is less than 30 parts by weight, the melt viscosity of the interlayer film for laminated glass increases, and the deaeration during the production of laminated glass may decrease. When content of the said plasticizer exceeds 70 weight part, a plasticizer may raise | generate a bleed-out from the intermediate film for laminated glasses. The minimum with more preferable content of the said plasticizer is 35 weight part, and a more preferable upper limit is 60 weight part.

The interlayer film for laminated glass of the present invention contains a light absorber having an anthraquinone structure having a thiophenyl group.

Since the interlayer film for laminated glass of the present invention contains a light absorber having an anthraquinone structure having a thiophenyl group, the ultraviolet transmittance can be lowered while maintaining a high visible light transmittance. Furthermore, since the light absorber having an anthraquinone structure having a thiophenyl group hardly deteriorates even when irradiated with ultraviolet rays, an interlayer film for laminated glass having excellent light resistance can be obtained.

The light absorber having an anthraquinone structure having a thiophenyl group may have at least one thiophenyl group, and preferably has two or more thiophenyl groups. For example, examples of the light absorber having an anthraquinone structure having a thiophenyl group include 1,8-bis (phenylthio) -9,10-anthraquinone represented by the following chemical formula (1). Among them, 1,8-bis (phenylthio) -9,10- is capable of reducing the ultraviolet transmittance while maintaining high visible light transmittance, adjusting the color tone to light yellow, and being excellent in light resistance. It is preferable to use anthraquinone.
In addition, the light absorber which has an anthraquinone structure which has a thiophenyl group may be used independently, and 2 or more types may be used together.

The lower limit of the content of the light absorber having an anthraquinone structure having a thiophenyl group in the interlayer film for laminated glass of the present invention is 0.003 parts by weight with respect to 100 parts by weight of the thermoplastic resin, and the upper limit is 0.007 weights. Part. When the content of the light absorber having an anthraquinone structure having a thiophenyl group is less than 0.003 parts by weight, the ultraviolet transmittance may not be sufficiently lowered, and when it exceeds 0.007 parts by weight, It becomes difficult to adjust the color tone of the obtained interlayer film for laminated glass to light yellow. The minimum with preferable content of the light absorber which has the anthraquinone structure which has the said thiophenyl group is 0.0035 weight part, and a preferable upper limit is 0.0067 weight part.

The interlayer film for laminated glass according to the present invention may contain, if necessary, an ultraviolet absorber, an antioxidant, a light stabilizer, a flame retardant, an antistatic agent, an adhesive force adjusting agent, a moisture resistance agent, a blue pigment, a blue dye, and a green pigment. , Green dyes, fluorescent brighteners, infrared absorbers and other additives.

The infrared absorber is not particularly limited as long as it has the ability to shield infrared rays, but in the present invention, tin-doped indium oxide fine particles, antimony-doped tin oxide fine particles, zinc oxide fine particles doped with metal elements, lanthanum hexaboride It is preferable to contain at least one selected from the group consisting of fine particles, zinc antimonate fine particles, and an infrared absorber having a phthalocyanine structure.

Although content of the said infrared absorber is not specifically limited, The preferable minimum of content of the said infrared absorber is 0.001 weight part with respect to 100 weight part of said thermoplastic resins, and a preferable upper limit is 5 weight part. When the content of the infrared absorber is less than 0.001 part by weight, the interlayer film for laminated glass may not be able to shield infrared rays. When content of the said infrared absorber exceeds 5 weight part, the transparency of a laminated glass may fall.

The thickness of the interlayer film for laminated glass of the present invention is not particularly limited, but a preferable lower limit is 0.1 mm and a preferable upper limit is 3 mm. When the thickness of the interlayer film for laminated glass is less than 0.1 mm, the penetration resistance of the obtained laminated glass may be lowered. When the thickness of the interlayer film for laminated glass exceeds 3 mm, the transparency of the interlayer film for laminated glass obtained may be lowered. The more preferable lower limit of the thickness of the interlayer film for laminated glass is 0.25 mm, and the more preferable upper limit is 1.5 mm.

The interlayer film for laminated glass of the present invention has a visible light transmittance Tv of 60% or more measured by a method according to JIS R 3106 with a thickness of 760 μm and sandwiched by a clear glass with a thickness of 2.5 mm. It is preferable. When the visible light transmittance Tv is less than 60%, the transparency of the laminated glass obtained using the interlayer film for laminated glass of the present invention is lowered. The visible light transmittance Tv is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more.
In addition, the apparatus which measures the said visible light transmittance | permeability Tv is not specifically limited, For example, a spectrophotometer ("U-4000" by Hitachi, Ltd.) etc. are mentioned.

Since the interlayer film for laminated glass of the present invention contains the light absorber having an anthraquinone structure having the thiophenyl group at a specific ratio, an interlayer film for laminated glass having excellent light resistance can be obtained. In the present invention, being excellent in light resistance means that even when used in an environment irradiated with ultraviolet rays, it is possible to suppress an increase in light transmittance in a wavelength range of 380 to 410 nm over time.
The evaluation of light resistance in the present invention is performed by irradiating the obtained laminated glass with ultraviolet rays for 2000 hours using an ultraviolet irradiation device (“HLG-2S” manufactured by Suga Test Instruments Co., Ltd.) and the like. The degree of change (ΔT (410 nm)) in light transmittance at 410 nm of the laminated glass before and after ultraviolet irradiation is calculated and evaluated by the following formula. In addition, the apparatus which measures the light transmittance in 410 nm is not specifically limited, For example, a spectrophotometer (Hitachi Ltd. make "U-4000") etc. are mentioned.
ΔT (410 nm) = (light transmittance after UV irradiation (410 nm)) − (light transmittance before UV irradiation (410 nm))

The degree of change (ΔT (410 nm)) is not particularly limited, but is preferably 2.5 or less. If the degree of change (ΔT (410 nm)) exceeds 2.5, the light resistance of the laminated glass obtained using the interlayer film for laminated glass of the present invention may not be sufficiently obtained. The degree of change (ΔT (410 nm)) is more preferably 2.3 or less, and even more preferably 2.0 or less.

Since the interlayer film for laminated glass of the present invention contains the light absorber having the anthraquinone structure having the thiophenyl group at a specific ratio, the color tone of the laminated glass can be controlled to be pale yellow. The color tone of the laminated glass can be evaluated by yellowness (yellow index).
The yellowness is measured by a method in accordance with JIS K 7105 by measuring the interlayer film for laminated glass of the present invention with a clear glass having a thickness of 760 μm and a thickness of 2.5 mm. Can measure the yellowness. In addition, the apparatus which measures the said yellow degree is not specifically limited, For example, a spectrophotometer (Hitachi Ltd. make "U-4000") etc. are mentioned.

The yellowness is not particularly limited, but is preferably 18 or less. When the yellowness exceeds 18, the color tone of the laminated glass obtained by using the interlayer film for laminated glass of the present invention may not be pale yellow, which may be associated with deterioration of the interlayer film for laminated glass. . The yellowness is more preferably 17 or less.

As a method for producing the interlayer film for laminated glass of the present invention, a plasticizer containing a light absorber having an anthraquinone structure having a thiophenyl group, and adding an additive to be blended as necessary, Examples thereof include a method of sufficiently kneading a thermoplastic resin such as a polyvinyl acetal resin to form an interlayer film for laminated glass.
In particular, the method may include a step of preparing a composition in which a light absorber having an anthraquinone structure having a thiophenyl group is dissolved in a plasticizer, and a step of kneading the composition and a thermoplastic resin such as a polyvinyl acetal resin. preferable.
In the step of producing a composition in which a light absorber having an anthraquinone structure having a thiophenyl group is dissolved in a plasticizer, the composition is preferably heated in order to dissolve the light absorber.

The method for kneading the composition and the thermoplastic resin is not particularly limited, and examples thereof include a method using an extruder, a plastograph, a kneader, a Banbury mixer, a calender roll, and the like. Especially, since it is suitable for continuous production, the method using an extruder is suitable, and the method using a twin-screw extruder is more suitable.

Laminated glass using the interlayer film for laminated glass of the present invention is also one aspect of the present invention. It does not specifically limit as plate glass used for the laminated glass of this invention, The transparent plate glass generally used can be used, for example, float plate glass, polished plate glass, type | mold plate glass, netted glass, lined plate glass, coloring Examples thereof include inorganic glass such as prepared plate glass, heat ray absorbing glass, heat ray reflecting glass, and green glass. Moreover, organic plastics boards, such as a polycarbonate and a polyacrylate, can also be used.

As the plate glass, two or more types of plate glasses may be used. For example, the laminated glass which pinched | interposed the intermediate film for laminated glasses of this invention by transparent float plate glass and colored plate glass like green glass is mentioned.
The laminated glass of the present invention can be used as a windshield, a side glass, a rear glass, a roof glass, or a panoramic glass when used as an automotive glass.
Moreover, it does not specifically limit as a manufacturing method of the laminated glass of this invention, A conventionally well-known manufacturing method can be used.

According to the present invention, while maintaining a high visible light transmittance, it is possible to reduce the ultraviolet transmittance and control the color tone to light yellow, and the interlayer film for laminated glass having excellent light resistance, and the laminated Glass can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of interlayer film for laminated glass 39.3 parts by weight of triethylene glycol di-2-ethylhexanoate (3GO) as a plasticizer and 2,6-di-t-butyl-p- as an antioxidant 0.28 parts by weight of cresol, 0.2 parts by weight of an ultraviolet absorber (“Biosorb 550” manufactured by Kyodo Yakuhin Co., Ltd.), and 1,8-bis (phenylthio) -9 as a light absorber having an anthraquinone structure having a thiophenyl group , 10-anthraquinone 0.0035 part by weight was added and stirred at 80 ° C. for 30 minutes using a stirrer to obtain a plasticizer solution.
Next, after the obtained plasticizer solution was cooled to room temperature, a triethylene glycol di-2-ethylhexanoate (3GO) solution in which tin-doped indium oxide (ITO) fine particles were previously dispersed at a concentration of 30% by weight. 1 part by weight (hereinafter also referred to as ITO solution) was added and stirred for 10 minutes using a stirrer to obtain a mixed solution.
The obtained mixed solution was sufficiently mixed with 100 parts by weight of polyvinyl butyral resin (PVB), and formed into a film using a biaxial anisotropic extruder to produce an interlayer film for laminated glass having a film thickness of 760 μm.

(2) Production of laminated glass The obtained interlayer film for laminated glass was sandwiched between two pieces of clear glass (length 300 mm × width 300 mm × thickness 2.5 mm) to obtain a laminate. The obtained laminate was placed in a vacuum bag, and the vacuum bag was degassed at a reduced pressure of 933.2 hPa at room temperature. Next, while maintaining the deaerated state, the inside of the vacuum bag was heated to 100 ° C., and after reaching 100 ° C., the deaerated state was maintained for 20 minutes. Thereafter, the vacuum bag was naturally cooled to obtain a temporarily bonded laminated glass. The temporarily bonded laminated glass was pressure bonded for 20 minutes under the conditions of 135 ° C. and pressure 1.2 MPa using an autoclave to produce a laminated glass.

(Example 2)
An interlayer film for laminated glass and laminated glass were obtained in the same manner as in Example 1 except that the content of the light absorber having an anthraquinone structure having a thiophenyl group was changed to 0.0067 parts by weight.

(Comparative Example 1)
An interlayer film for laminated glass and laminated glass were obtained in the same manner as in Example 1 except that the light absorber having an anthraquinone structure having a thiophenyl group was not used.

(Comparative Example 2)
An interlayer film for laminated glass and laminated glass were obtained in the same manner as in Example 1 except that the content of the light absorber having an anthraquinone structure having a thiophenyl group was changed to 0.008 parts by weight.

(Comparative Example 3)
Instead of 0.0035 parts by weight of light absorber having an anthraquinone structure having a thiophenyl group, 0.0035 parts by weight of light absorber A (Kayaset Yellow AG “manufactured by Nippon Kayaku Co., Ltd.”) and light absorber B An intermediate film for laminated glass and laminated glass were obtained in the same manner as in Example 1 except that 1 part by weight (Plast Yellow 8000 “manufactured by Arimoto Chemical Co., Ltd.)” was used.

(Comparative Example 4)
An interlayer film for laminated glass as in Example 1 except that light absorber B (Plast Yellow 8000 “manufactured by Arimoto Chemical Co.”) was used instead of the light absorber having an anthraquinone structure having a thiophenyl group, And the laminated glass was obtained.

<Evaluation>
The following evaluation was performed about the laminated glass obtained by the Example and the comparative example. The results are shown in Table 1.

(1) Measurement of transmittance Using a spectrophotometer (“U-4000” manufactured by Hitachi, Ltd.), the obtained laminated glass (length 300 mm × width 300 mm) is visible according to JIS R 3106 (1998). The light transmittance Tv was determined. Moreover, the solar radiation transmittance Ts in the wavelength range of 300 to 2500 nm of the obtained laminated glass was determined.
Further, using a spectrophotometer (“U-4000” manufactured by Hitachi, Ltd.), the light transmittance (T (370 nm), T (380 nm)) of laminated glass at each wavelength of 370 nm, 380 nm, 390 nm, 400 nm and 410 nm, T (390 nm), T (400 nm), T (410 nm)) were measured.

(2) Measurement of haze value The obtained laminated glass (length 300 mm × width 300 mm) was cut into a size of length 50 mm × width 50 mm. Next, using a haze meter (“TC-H3PP type” manufactured by Tokyo Denshoku Co., Ltd.), in accordance with JIS K 7105 (1981) “Testing method for optical properties of plastic”, the obtained laminated glass (length 50 mm × A haze value of 50 mm in width) was measured.

(3) Measurement of yellowness Yellow using a spectrophotometer (“U-4000” manufactured by Hitachi, Ltd.) and transmission method of the obtained laminated glass (length 300 mm × width 300 mm) according to JIS K 7105 The degree (yellow index) was measured.

(4) Light resistance evaluation Using an ultraviolet irradiation device (“HLG-2S” manufactured by Suga Test Instruments Co., Ltd.), ultraviolet light (quartz glass) was applied to the obtained laminated glass (length 50 mm × width 50 mm) in accordance with JIS R 3205. A mercury lamp (750 W) was irradiated for 2000 hours. The degree of change in light transmittance (ΔT (410 nm)) at 410 nm of the laminated glass before and after UV irradiation was calculated by the following formula. The light transmittance at 410 nm was measured with a spectrophotometer (“U-4000” manufactured by Hitachi, Ltd.).
ΔT (410 nm) = (light transmittance after UV irradiation (410 nm)) − (light transmittance before UV irradiation (410 nm))

The laminated glasses obtained in Examples 1 and 2 were able to reduce the ultraviolet transmittance, particularly in the wavelength region of 400 nm or less, while maintaining high visible light transmittance. Moreover, the laminated glass of this invention was able to control the color tone of the laminated glass to light yellow by making content of the light absorber which has the anthraquinone structure which has the said thiophenyl group into a specific ratio. Furthermore, the laminated glass of the present invention had excellent light resistance as shown in the light resistance evaluation.
On the other hand, in Comparative Example 1, the ultraviolet transmittance in the wavelength region of 400 nm or less could not be sufficiently reduced. In addition, it is thought that the light resistance evaluation result of the comparative example 1 is caused by deterioration of the polyvinyl butyral resin. In Comparative Example 2, the content of the light absorber having the anthraquinone structure having the thiophenyl group was excessive, so that the color tone of the laminated glass became very strong yellow. In Comparative Example 3, since another light absorber was used, the color tone of the laminated glass became very strong yellow. In Comparative Example 4, the visible light transmittance was maintained and the ultraviolet transmittance could be reduced, but it was confirmed that the light transmittance at 410 nm increased after the light resistance evaluation.

According to the present invention, while maintaining a high visible light transmittance, it is possible to reduce the ultraviolet transmittance and control the color tone to light yellow, and the interlayer film for laminated glass having excellent light resistance, and the laminated Glass can be provided.

Claims (2)

An interlayer film for laminated glass containing a thermoplastic resin, a plasticizer, and a light absorber having an anthraquinone structure having a thiophenyl group,
The interlayer film for laminated glass, wherein the content of the light absorber is 0.003 to 0.007 parts by weight with respect to 100 parts by weight of the thermoplastic resin. A laminated glass comprising the interlayer film for laminated glass according to claim 1.