CA1123538A - Light-polarizing film - Google Patents
Light-polarizing filmInfo
- Publication number
- CA1123538A CA1123538A CA325,192A CA325192A CA1123538A CA 1123538 A CA1123538 A CA 1123538A CA 325192 A CA325192 A CA 325192A CA 1123538 A CA1123538 A CA 1123538A
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- carbon atoms
- light
- group
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- polarizing film
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Abstract
The specification discloses a light-polarizing film comprising a polymer mixture containing a polymer having polyene chains formed by partial dehydrohalogenation of a halogenated vinyl polymer or a halogenated vinylidene polymer and acrylate polymers or methacrylate polymers. The light-polarizing film has excellent heat stability as well as huimidity resistance and is useful in various fields including liquid crystal device, optical device, etc.
Description
3~
The present invention relates to a light~polarizing film having good heat stability and humidity resistance.
A conventional light-polarizing film is produced by impregnating a film of polyvinyl alcohol (hereinafter referred to as PVA) or a derivative thereof with an aqueous solution of iodine or a dichromic dye, and then stretching the film by dry or wet heating so that high molecular micelles are unidirectionally oriented. How-ever, since PVA used as the base material is a hydrophilic polymer, the light-polarizing film thus obtained lacks humidity resistance.
We have previously developed a process ~or producing a hydrophobic light-polari~ing film (e.g. as described in our United States Patent No. 3,621,085 issued on November 16, 1971). In this process, a halogenated vinyl polymer or a halogenated vinylidene polymer is reacted with a dehydrohalogenating agent to form polyene chains (con-jugated double bonds) in the molecule and the polyene chains are unidirectionally orientaed in the film of the pol~mer to obtain a light-polarizin~ film.
However, these conventional light-polarizing films, including our hydrophobic film mentioned above, are still somewhat inadequate with respect to heat stability. For example, a light polarizing Eilm having PVA as the base material should be used at a temperature of not more than ~0C over long periods of time, and at the most at 60C
for even short periods of time. In the case of our hydrophobic light-polarizing film mentioned above, the ~ilm changes in color and darkens, thus reducing light transmittance, when it is continuously used at 60C for a long period of time (e.g. for several days).
3~
Accordingly, the use of light-polarizing films has hltherto been limited by such drawbacks and it would be desirable in various fields of use to improve the heat resistance of light-polarizing films. This is particu-larly true in the case of liquid crystal display devices in which light-polarizing films are expected to play an expanding role. It is required that light-polarizing films for this use have a sufficiently high stability to dry and wet heating to be continuously used at 60 to 70 C
for a long period of time.
We have made intensive studies of the improvement of light-polarizing films in an attempt to satisfy these requirements and have found that the heat stability of a light-polarizing film can be remarkably improved while maintaining excellent humidity resistance and polariza-tion efficiency by homogeneously distributing an acrylate and/or methacrylate polymer in a conventional polyene-containing light-polarizing film.
The main object of the present invention is to provide a light-polarizing film having improved heat resistance and stability as ~ell as good humidity resistance and good polarization efficiency. `~
According to the present invention there is provided a light-polarizing film comprising a polymer mixture of a polymer having polyene chains formed by partial dehydro-halogenation of a halogenated vinyl polymer or a halogen-ated vinylidene polymer and one or more of the polymers selected from the group consisting of acrylate polymers and methacrylate polymers.
The light-polarizing film of the present invention can ; , be produced by various processes.
.
- .
. . .
~.23~
For example, the light-polarizing film can be pro-duced by substantlally the same processes as employed for producing known polyene-containing light-polarizing film.
In the light-polarizing film of the present invention, an acrylate and/or methacrylate polymer is merely homo-geneously distributed in the conventional film which displays the polarization effect by unidirectional orientation of a polymer having polyene chains. That is, the light-polarizing film of the present invention can be produced by homogeneously admixing an acrylate polymer or a methacrylate polymer with all the other components of the film and with any other ~ilm-forming polymers at any stage of a conventional process for producing polyene-containing films which comprises partially dehydrohalo-genating a halogenated vinyl polymer or a halogenated vinylidene polymer to form polyene chains in the molecule thereof and then unidirectionally orienting the polyene chains in the film.
The formation of polyene chains can be carried out in one step or in two steps but, pre~erably, in the present invention, it is carried out in two steps. Firstly, a halogenated vinyl polymer or a halogenated vinylidene polymer is partially dehydrohalogenated with a dehydro-halogenating agent to form polyene chains. The polymer is subjected to the dehydrohalogenation in the ~orm of a solution or a solid such as a suspension or film. Then, the dehydrohalogenated product is further dehydrohalo-genated by heating which causes the polyene chains to grow in size in the polymer.
For example, the li~ht-polarizing film of the present invention can be produced by reacting a halogenated vinyl .
~ ' , 3~3~
polymer or a halogenated vinylidene polymer with a de-hydrohalogenating agent in a solvent either after or before the addition thereto of an acrylate polymer or a methacrylate polymer and, if necessary, one or more other polymers, until the dehydrohalogenation degree (i.e. the ratio of halogen atoms removed as hydrogen halide to the total halogen atoms in the polymer used~ reaches 0.1 to 20 mol%, casting the solution thus obtained into a film, heating the film preferably to 70 to 150C to cause the polyene chains to grow and then unidirectionally orienting the resulting polyene-containing film.
Alternatively, the light-polarizing film of the present invention can be produced by admixing an acrylate polymer or a methacrylate polymer with a halogenated vinyl polymer or a halogenated vinylidene polymer, forming the mixture into a film of 5 to 500 ~in thickness by a normal method, such as calendering, extruding or casting, react-ing the film with a dehydrohalogenating agent in a non-solvent or a swelling agent for the film to obtain a yellowish film, removing the dehydrohalogenating agent by washing, heating the film at 70 to 150C to cause the polyene chains formed therein to grow and then stretching the film in one direction.
The light-polarizing film of the present invention preferably has an average light transmittance of 10 to 70 %, more preferably 20 to 70 ~, at wavelengths in the range of 450 to 700 m ~ ti.e. the average of light trans-mittance measured within the wavelength range at intervals of 10 m~), and a ratio of the average percent of light transmitted with the polari2ation axes parallel (Ho) to the average percent of light transmitted with the - ~ . .
: ' ~
3~
polarization axes crossed (Hgo) of Ho/Hgo_2r more preferably, Ho/Hgo_4~
When the above light transmittance is too low, the brightness of the film is insufficient. On the other hand, when the above light transmittance is too high, the polarization efficiency of the film is insufficient.
Further, when the Ho/Hgo ratio is too low, a good contrast cannot be obtained and there is insuEficient difference between a bright part and a dark part when the film is used in a liquid crystal display device.
Generally, when the value of percent light transmitted with the polarization axes parallel (i.e. the light transmittance of two films overlapping in the parallel position with respect to the polarization axes) and the value of percent light transmitted with the polar ization axes crossed (i.e. the light transmittance of ` two films overlapping at right angles with respect to the ; polarization axes) are used as a measure of polarization efficiency of a light-polarizing f.ilm and the ratio or difference of these two values is large, the difference in contrast of bright-and dark between two films overlapping in the parallel position and at right angles with respect to the polarization axes is large. Usually, corresponding to the above average light transmittance, Ho and Hgo at the wave-length of 450 to 700 m~ of the light-polarizing film of the present invention are l0 to 55 %, preferably 25 to 45 %, and 0.01 to 45 %, preferably 0.01 to 20 ~, ; respectively.
The thickness of the light-polarizing film of the present invention is not critical but is usually in the .
.
, ' ' .
3~
range of 1 to 200 ~, preferably 5 to 50~.
The acrylate or methacrylate polymer used in the present invention may be a homopolymer or a copolymer of a monomer of the formula:
Rl CH2 = C - COOR2 (I) in which Rl is hydrogen or an alkyl group having 1 to 10 carbon atoms (preferably hydrogen or methyl); and R2 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or bicycloalkyl group having 5 to 10 carbon atoms (e.q.
cyclohexyl, isomenthyl, isobornyl, etc.), an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.), an aralkyl group having 7 to 10 carbon atoms (e.g. benzyl, p-isopropylbenzyl etc.) or a heterocyclic group containing one or more hetero atoms selected from O, N and S (e.g.
furfuryl, thienyl etc.) and the alkyl chain of the group R2 may be interrupted with O, N or S and the alkyl or aryl group may be substituted with one or more halogens (e.g. bromine, etc.). Further, the acrylate or meth- `
acrylate polymer may include a copolymer of the above monomer (I) and up to 50 mol % (based on all the struc~
tural units of the polymer) of another copolymerizable monomer of the formula:
' .
The present invention relates to a light~polarizing film having good heat stability and humidity resistance.
A conventional light-polarizing film is produced by impregnating a film of polyvinyl alcohol (hereinafter referred to as PVA) or a derivative thereof with an aqueous solution of iodine or a dichromic dye, and then stretching the film by dry or wet heating so that high molecular micelles are unidirectionally oriented. How-ever, since PVA used as the base material is a hydrophilic polymer, the light-polarizing film thus obtained lacks humidity resistance.
We have previously developed a process ~or producing a hydrophobic light-polari~ing film (e.g. as described in our United States Patent No. 3,621,085 issued on November 16, 1971). In this process, a halogenated vinyl polymer or a halogenated vinylidene polymer is reacted with a dehydrohalogenating agent to form polyene chains (con-jugated double bonds) in the molecule and the polyene chains are unidirectionally orientaed in the film of the pol~mer to obtain a light-polarizin~ film.
However, these conventional light-polarizing films, including our hydrophobic film mentioned above, are still somewhat inadequate with respect to heat stability. For example, a light polarizing Eilm having PVA as the base material should be used at a temperature of not more than ~0C over long periods of time, and at the most at 60C
for even short periods of time. In the case of our hydrophobic light-polarizing film mentioned above, the ~ilm changes in color and darkens, thus reducing light transmittance, when it is continuously used at 60C for a long period of time (e.g. for several days).
3~
Accordingly, the use of light-polarizing films has hltherto been limited by such drawbacks and it would be desirable in various fields of use to improve the heat resistance of light-polarizing films. This is particu-larly true in the case of liquid crystal display devices in which light-polarizing films are expected to play an expanding role. It is required that light-polarizing films for this use have a sufficiently high stability to dry and wet heating to be continuously used at 60 to 70 C
for a long period of time.
We have made intensive studies of the improvement of light-polarizing films in an attempt to satisfy these requirements and have found that the heat stability of a light-polarizing film can be remarkably improved while maintaining excellent humidity resistance and polariza-tion efficiency by homogeneously distributing an acrylate and/or methacrylate polymer in a conventional polyene-containing light-polarizing film.
The main object of the present invention is to provide a light-polarizing film having improved heat resistance and stability as ~ell as good humidity resistance and good polarization efficiency. `~
According to the present invention there is provided a light-polarizing film comprising a polymer mixture of a polymer having polyene chains formed by partial dehydro-halogenation of a halogenated vinyl polymer or a halogen-ated vinylidene polymer and one or more of the polymers selected from the group consisting of acrylate polymers and methacrylate polymers.
The light-polarizing film of the present invention can ; , be produced by various processes.
.
- .
. . .
~.23~
For example, the light-polarizing film can be pro-duced by substantlally the same processes as employed for producing known polyene-containing light-polarizing film.
In the light-polarizing film of the present invention, an acrylate and/or methacrylate polymer is merely homo-geneously distributed in the conventional film which displays the polarization effect by unidirectional orientation of a polymer having polyene chains. That is, the light-polarizing film of the present invention can be produced by homogeneously admixing an acrylate polymer or a methacrylate polymer with all the other components of the film and with any other ~ilm-forming polymers at any stage of a conventional process for producing polyene-containing films which comprises partially dehydrohalo-genating a halogenated vinyl polymer or a halogenated vinylidene polymer to form polyene chains in the molecule thereof and then unidirectionally orienting the polyene chains in the film.
The formation of polyene chains can be carried out in one step or in two steps but, pre~erably, in the present invention, it is carried out in two steps. Firstly, a halogenated vinyl polymer or a halogenated vinylidene polymer is partially dehydrohalogenated with a dehydro-halogenating agent to form polyene chains. The polymer is subjected to the dehydrohalogenation in the ~orm of a solution or a solid such as a suspension or film. Then, the dehydrohalogenated product is further dehydrohalo-genated by heating which causes the polyene chains to grow in size in the polymer.
For example, the li~ht-polarizing film of the present invention can be produced by reacting a halogenated vinyl .
~ ' , 3~3~
polymer or a halogenated vinylidene polymer with a de-hydrohalogenating agent in a solvent either after or before the addition thereto of an acrylate polymer or a methacrylate polymer and, if necessary, one or more other polymers, until the dehydrohalogenation degree (i.e. the ratio of halogen atoms removed as hydrogen halide to the total halogen atoms in the polymer used~ reaches 0.1 to 20 mol%, casting the solution thus obtained into a film, heating the film preferably to 70 to 150C to cause the polyene chains to grow and then unidirectionally orienting the resulting polyene-containing film.
Alternatively, the light-polarizing film of the present invention can be produced by admixing an acrylate polymer or a methacrylate polymer with a halogenated vinyl polymer or a halogenated vinylidene polymer, forming the mixture into a film of 5 to 500 ~in thickness by a normal method, such as calendering, extruding or casting, react-ing the film with a dehydrohalogenating agent in a non-solvent or a swelling agent for the film to obtain a yellowish film, removing the dehydrohalogenating agent by washing, heating the film at 70 to 150C to cause the polyene chains formed therein to grow and then stretching the film in one direction.
The light-polarizing film of the present invention preferably has an average light transmittance of 10 to 70 %, more preferably 20 to 70 ~, at wavelengths in the range of 450 to 700 m ~ ti.e. the average of light trans-mittance measured within the wavelength range at intervals of 10 m~), and a ratio of the average percent of light transmitted with the polari2ation axes parallel (Ho) to the average percent of light transmitted with the - ~ . .
: ' ~
3~
polarization axes crossed (Hgo) of Ho/Hgo_2r more preferably, Ho/Hgo_4~
When the above light transmittance is too low, the brightness of the film is insufficient. On the other hand, when the above light transmittance is too high, the polarization efficiency of the film is insufficient.
Further, when the Ho/Hgo ratio is too low, a good contrast cannot be obtained and there is insuEficient difference between a bright part and a dark part when the film is used in a liquid crystal display device.
Generally, when the value of percent light transmitted with the polarization axes parallel (i.e. the light transmittance of two films overlapping in the parallel position with respect to the polarization axes) and the value of percent light transmitted with the polar ization axes crossed (i.e. the light transmittance of ` two films overlapping at right angles with respect to the ; polarization axes) are used as a measure of polarization efficiency of a light-polarizing f.ilm and the ratio or difference of these two values is large, the difference in contrast of bright-and dark between two films overlapping in the parallel position and at right angles with respect to the polarization axes is large. Usually, corresponding to the above average light transmittance, Ho and Hgo at the wave-length of 450 to 700 m~ of the light-polarizing film of the present invention are l0 to 55 %, preferably 25 to 45 %, and 0.01 to 45 %, preferably 0.01 to 20 ~, ; respectively.
The thickness of the light-polarizing film of the present invention is not critical but is usually in the .
.
, ' ' .
3~
range of 1 to 200 ~, preferably 5 to 50~.
The acrylate or methacrylate polymer used in the present invention may be a homopolymer or a copolymer of a monomer of the formula:
Rl CH2 = C - COOR2 (I) in which Rl is hydrogen or an alkyl group having 1 to 10 carbon atoms (preferably hydrogen or methyl); and R2 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or bicycloalkyl group having 5 to 10 carbon atoms (e.q.
cyclohexyl, isomenthyl, isobornyl, etc.), an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.), an aralkyl group having 7 to 10 carbon atoms (e.g. benzyl, p-isopropylbenzyl etc.) or a heterocyclic group containing one or more hetero atoms selected from O, N and S (e.g.
furfuryl, thienyl etc.) and the alkyl chain of the group R2 may be interrupted with O, N or S and the alkyl or aryl group may be substituted with one or more halogens (e.g. bromine, etc.). Further, the acrylate or meth- `
acrylate polymer may include a copolymer of the above monomer (I) and up to 50 mol % (based on all the struc~
tural units of the polymer) of another copolymerizable monomer of the formula:
' .
2 = C \ (II) in whch R3 is hydrogen or an alkyl group having 1 to 10 carbon atoms (preferably, hydrogen or methyl); and R4 is a hydrocarbon group having 1 to 10 carbon atoms such as an alkyl group ha~7ing 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.l,
3~
or a cycloalkyl ~ro-lp or bicycloalkyl group having ~ to 10 carbon atoms (e.g. cyclohexyl, etc.), a heterocyclic group having one or more hetero a~oms selected grom O, N and S
(e.g. furfuryl, thienyl etc.), -CN, -OH or -OOCR5; R5 is an alkyl group having 1 to 10 carbon atoms and the alkyl chain of the groups R4 and R5 may be interrupted with O, N, S, or -COO- and the group R4 may be substi-tuted with one or more OH or halogens (e.g. bromine, etc.).
Examples of the acrylate or methacrylate polymer are homopolymers such as polymethyl methacrylate, polyethy methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethyl acrylate and the like; bipolymers such as methyl methacrylate-ethyl methacrylate copolymer, methyl methacrylate-propyl methacrylate copolymer, methyl methacry-late-butyl methacrylate copolymer, ethyl methacrylate-propyl methacrylate copolymer, methyl methacrylate-methyl acrylate copolymer, ethyl methacrylate-methyl acrylate copolymer, ; methyl methacrylate-ethyl acrylate copolymer, methyl acrylate-methyltri~lycol acrylate copolymer, methyl methacrylate-methyltriglycol acrylate copolymer, methyl methacrylate-stearyl acrylate copolymer, methyl methacrylate-stearyl methacrylate copolymer, ethyl methacrylate-ethy acrylate copolymer, methyl methacryla-te-butyl acrylate copolymer, methyl methacrylate-propyl acrylate copolymer, methyl methacrylate-2-hydroxyethyl methacrylate copolymer, methyl methacrylate-2-hydroxypropyl methacrylate copolymer, ethyl methacrylate-2-hydroxyethyl methacrylate copolymer, ethyl methacrylate-2-hydroxypropyl methacrylate copolymer,methyl - " ~h~.~;3~3~
ethacrylate-2-hydroxyethyl acrylate copolymer, methyl methacrylate-2-hydroxypropyl acrylate copolymer, ethyl methacrylate-2-hydroxyethyl acrylate copolymer, ethyl meth-acrylate-2-hydro~ypropyl acrylate copolymer, methyl meth-acrylate-tetrahydrofurfuryl acrylate copolymer, methyl methacrylate-tetrahydro~urfuryl methacrylate copolymer, ethyl methacrylate-tetrahydrofurfuryl acrylate copolymer, ethyl me~hacrylate tetrahydrofurfuryl methacrylate copolymer, methyl methacrylate-benzyl acrylate copolymer, methyl methacrylate-benzyl methacrylate copolymer, methyl meth-acrylate-benzyl acrylate copolymer, methyl methacrylate- : ;
phenoxyethyl acrylate copolymer, methyl methacrylate-phenoxy-ethyl methacrylate copolymer, methyl methacrylate-cyclohexyl acrylate copolymer, methyl methacrylate-cyclohexyl meth-acrylate copolymer, methyl methacrylate-glycidyl acrylate copolymer, methyl methacrylate-ylycidyl methacrylate copolymer, ethyl methacrylate-tribromophenyl acrylate copolymer methyl methacrylate-dibromopropyl acrylate copolymer, methyl methacrylate-tropine acrylate copolyme~, methyl methacry-late-tropine methacrylate copolymer, methyl acrylate-tropine methacrylate copolymer, ethyl methacrylate-tropine acrylate copolymer, methyl methacrylate-isobornyl methacrylate co-polymer, methyl methacrylate-isobornyl acrylate copolymer, ethyl methacrylate-isobornyl methacrylate copolymer, propyl methacrylate-isobornyl methacrylate copolymer, methyl methacrylate-lsomenthyl acrylate copolymer, metyl meth-acrylate~isomenthyl methacrylate copolymer, ethyl meth-acrylate~isomenthyl methacrylate copolymer,methyl acrylate~
:~ acrylonitrile copolymer, butyl acrylate-acrylonitrile copolymer, n~propyl acrylate~acrylonitrile copolymer and the like; and terpolymers such as methy methacrylate~ethyl methacrylate~
~ 8 ~
3~
butyl Methacrylate copolymer, methyl methacrylate-ethyl methacrylate-methyl acrylate copolymer, methyl methacrylate-ethyl methacrylate methyltriglycol acrylate copolymer, methyl methacrylate-ethyl methacrylate-stearyl acrylate co-polymer, methyl methacrylate-ethyl methacrylate-stearyl methacrylate copolymer, methyl methacrylate-ethyl meth-acrylate-tetrahydrofurfuryl acrylate copolymer, methyl methacrylate-ethyl methacrylate-tetrahydrofurfuryl meth-acrylate copolymer, methyl methacrylate-ethyl methacrylate-benzyl acrylate copolymer, methyl methacrylate-ethyl meth-acrylate-benzyl methacrylate copolymer, methyl methacrylate-ethyl methacrylate-phenoxyethyl acrylate copolymer, methyl methacrylate-ethyl methacrylate-phenoxyethyl methacrylate copolymer, methyl methacrylate-ethyl methacrylate-cyclo-hexyl acrylate copolymer, methyl methacrylate-ethyl meth-acrylate-cyclohexyl methacrylate copolymer, methyl meth-acrylate-ethyl methacrylate-glycidyl acrylate copolymer, methyl methacrylate-ethyl methacrylate-glycidyl methacrylate copolymer, methy methacrylate-ethyl me~thacrylate-tribromo-phenyl acrylate copolymer, methyl methacrylate-ethyl meth-acrylate-tribromophenyl methacrylate copolymer, ~ethyl methacrylate-ethyl methacrylate-dibromophenyl methacrylate copolymer, methyl methacryla-te-methyl acrylate-benzyl meth- :
acrylate copolymer, methyl methacrylate~methyl acrylate-cyclohexyl acrylate copolymer, methyl methacrylate-methyl acrylate-~lycidyl methacrylate copolymer, methyl methacry-late-methyl acrylate-tribromophenyl methacrylate copolymer and the like. These polymers can be used alone or in any combination thereof.
Preferably, the acrylate or methacrylate polymer is used in an amount of 5 to 95 % by weight, more preferably 3~3:~
5 to 35 ~ by weight, based on the total weight of the halogenated vinyl or vinylidene polymer used for the formation of polyene chains. When the amount of the polymer is less than 5 ~ by weight, the improvement in heat stability of the resulting light-polarizing film is low. On the other hand, when the amount of the polymer is more than 95 ~ by weight, the polyene concentration in the molecule is insufficient and the polarization efficiency is lowered.
The halogenated vinyl or vinylidene polymer used for the formation of polyene chains is preferably a homo- ~ ;
polymer or a copolymer of a monomer of the formula:
/R6 `~ ~ ~
CH2 = C \ (III) X
in which X is halogen (preferably, chlorine or bromine);
R6 is hydrogen, -CN, -COOR7, -OOCR8 or an aryl group having 6 to 10 carbon atoms (e.g phenyl, naphthyl, etc.);
R7 is an alkyl group having 1 to 10 carbon atoms; and R8 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.) or a cycloalkyl ~roup having 5 to 10 carbon atoms (e.g. cyclohexyl, etc.).
Typical examples of these polymers are a homopolymer ; or a copolymer of a vinyl halide and/or a vinylidene haIide such as vinyl chloride, vinyl bromide, vinylidene chloride and the like.
Further, the halogenated vinyl or vinylidene polymer -:
may include a copolymer of the above monomer (III) and up to 90 mol % (based on all the structural units of the polymer) of another copolymerizable monomer, preferably, .
3~
a monomer of the formula:
/
C~2 = C (IV) in ~hich Rg is hydrogen or an alkyl group having 1 to 10 carbon atoms; Rlo is hydrogen, a hydrocarbon group having 1 to 10 carbon atoms such as an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.) or a cycloalkyl groùp having 5 to 10 carbon atoms (e.g. cyclohexyl, etc.), a heterocyclic group having one or more hetero atoms sel-ected from O, N and S (e.g. furfuryl, thienyl etc.), -CN, -COORll, -OOCR12 or -OH; Rll is hydrogen or an alkyl group having 1 to 10 carbon atoms; R12 is an alkyl group having 1 to lQ carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.), or a cyclo-alkyl group having 5 to 10 carbon atoms (e.g. cyclohexyl etc.) and the alkyl chain of the groups Rll and R12 may be interrupted with O, N or S and the hydrocarbon group of Rlo may be substituted with one or more halogens.
When using a copolymer of a vinyl halide and a vinyli-dene halide and/or one or more other copolymerizable monomers, the copolymer must be in the form of a block copolymer or a graft copolymer so as to form polyene chains having suffisient chain length and it is preferable that the average chain length (polymeriæation degree) of a polyv~nyl halide block or a polyvinylidene halide block in the copolymer is more than 20. When the chain length is less than 20, it is difficult to obtain light-polarizing elements having sufficient activity within the visible ;~
:
.. :
light range. Further, it is preferable that the molar ratio of a vinyl halide or a vinylidene halide to all structural units of the polymer is 0.1/1 to 1/1, more preferably 0.5/1 to 1/1.
Examples of suitable block copolymers are as follows (they are shown by monomer structural units wherein "VC"
and "VB" stand for vinyl chloride and vinyl bromide, respectively):
VC-vinyl acetate, VC-acrylonitrile, VC-ethylene, VC-pro-pylene, VC-styrene, VC-butadiene, VC-isoprene, VC-vinyli-dene chloride, VC-acrylic acid, VC-methyl acrylate, VC-methyl methacrylate, VC-ethylene trifluoride, VB-vinyl acetate, VB-acrylonitrile, VB-ethylene, VB-propylene, VB-vinylidene chl~ride, VB-styrene, VB-acrylic acid, VB-methyl acrylate, VB-methyl methacrylate, VC-vinyl acetate-vinyl alcohol, VC-vinylidene chloride-methyl acrylate, VC-vinyl ~luoride-ethylene tetrafluoride, VB-styrene-methyl acrylate, ~-chlorovinylbenzene-vinylbenæene, ~-chloro-acrylonitrile-acrylonitrile, ~-chloroacrylonitrile-meth-acrylic acid. Suitable examples of the graft copolymerare polyvinyl chloride graft-copolymerized with methyl methacrylate or styrene, polyvinyl bromide graft-copoly-merized wlth styrene and the like.
These polymers or copolymers capable of formation of polyene chains can be used alone or in any combination thereof.
The light-polarizing film of the present invention preferably contains 5 to 95 ~ by weight of the acrylate or methacrylate polymer and 5 to 95 ~ by weight of the partially dehydrohalogenated halogenated vinyl or vinyli-dene polymer.
' ' If desired, one or more other film-forming polymers can be present in the light-polarizing film of the present invention together with the polymer having polyene chains and the acrylate or methacrylate polymer. Examples of these polymers are polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl aceta-te-vinyl alcohol copolymer, vinyl acetate-vinyl alcohol copolymer.
As described above, the formation of polyene chains can be carried out in one step with a dehydrohalogenating agent alone, or in two steps with a dehydydrohalogenating agent and then a heat treatment.
The dehydrohalogenating agent used in the present invention is, for example, a secondary or tertiary amine such as triethylamine, tri-n-propylamine, tri-n-butyl-amine, tri~n-amylamine, triethylened;aminediethylamine, di-n-propylamine and di-n-butylamine; an alkali metal alcoholate such as sodium methylate and sodium ethylate;
an amidine compound such as 1,8-diazabicyclol5.4.0]un-decene-7 and 1,5-diazabicyclo[4.3.0]nonene-5 and the like.
Although the preferred amount of the dehydrohalogen-ating agent depends upon the content of the partially dehydrohalogenated halogenated vinyl or vinylidene polymer and other polymer in the film, it is desirable to use more than 0.1 part by weight of the dehydrohalogenating agent per lO0 parts by weight of the halogenated vinyl or vinyli-dene polymer. When the amount of the dehydrohalogenating agent is less than 0.1 part by weight, the reaction rate is extremely low.
The dehydrogenation can be carried out in respect of 3~;3~
the polymer in the form of a solution or solid as described above.
The solvent which dissolves the polymer to be used and the dehydrohalogenating agent and is suitable for carrying out the dehydrohalogenation is, for example, dimethylformamide, diethylformamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, methyl ethyl ketone, a mixture thereof and the like.
When the dehydrohalogenation is carried out in the form of a solution, the dehydrohalogenating agent is desirably added to the polymer dissolved in the above solvent in an amount of 0.00001 to 1 mol ~, preferably 0.00002 to 0.4 mol %, based on the amount of the vinyl halide or vinylidene halide units in the polymer to be used.
When the dehydrohalogenation is carried out in the form of solid such as a film, the material to be dehydro-halogenated is treated with a solution o~ the dehydro-halogenating agent (concentration: 1 to 50 % by weight) in a good solvent thereof which does not dissolve the material (usually, n-hexane, n-heptane, isopropyl ether and the like can be used).
When forming the polyene chains in two steps, the treatment with the dehydrohalogenating agent is usually carried out at 5 to 150C, preferably at 20 to 100C, until the dehydrohalogenation degree reaches 0.1 to 20 mol ~, preEerably 0.2 to 10 mol %. The dehydrohalogen-ation degree can be calculated by the change of halogen content of the polymer used but the progress of the dehydrohalogenation can also be fairly exactly checked by the color change of the polymer or a solution thereof.
3~
That is, when the dehydrohalogenation is adequately carried out, the product has a yellow color whereas the product becomes orange, red or black when excess dehydro-halogenation takes place. Accordingly, the time when the reaction should be stopped can usually be decided by mon-itoring the change of the visible light transmittance curve of the reaction mixture to check the progress of the reac-tion (light absorption is initially observed in the near UV
range and gradually appears in a longer wavelength range).
In the molecule of the polymer thus partially dehydro-halogenated by the dehydrohalogenating agent, double bonds are distributed at random and polyene chains having short chain length are also partially formed. When the polymer is subsequently treated by heating, the growth of the polyene chains is initiated at these double bonds.
The heat treatment o~ the above deh~drohalogenated product is carried out in air or in an inert gas such as nitrogen at 50 to 150C, preferably at 60 to 130C, under atmospheric pressure or a reduced pressure.
During the heat treatment, the polyene chains grow with the progress of the treatment since the reaction is a chain reaction initiated at the double bonds which are ~ ;
already present in the molecule of the polymer. With the growth of the polyene chains, the light absorption of the reaction product within the visible light range increases and the color thereof changes to blue via violet.
~hen the reaction mixture is a blue color, its visible light transmittance curve shows a maximum absorption at wavelengths of 565 to 600 m~. Therefore, the heat treat-ment is preferably terminated when a maximum absorption of the reaction mixture is observed within or at least around ~ ~;3~3~
the abo~e wavelength and the light transmittance thereof at the wavelength of the maximum absorption reaches 0.001 to 60 ~, preferably 0.01 to 45 %. At this stage, 10 to 25 double bonds are linked in the polyene chains.
The heat treatment time necessary for the formation of polyene chains having sufficient length varies with the dehydrohalogenation degree (in the above treatment with the dehydrohalogenating agent) and other conditions but, usually, it is in the range of 2 minutes to 20 hours.
In any process, the polymer is dehydrohalogenated until the dehydrohalogenation degree finally reaches 0.1 to 30 mol %, usually 0.5 to 20 mol %.
After the dehydrohalogenation, the polyene chains formed in the polyvinyl or vinylidene halide are uni-directionally orientated by stretching a film formed from a polymer mi~ture comprising, as the main compounds, the polymer having polyene chains and the acrylate or meth-acrylate polymer. The stretching is carried out, for example, at 80 to 150C, preferably at 85 to 1~0C, when polyvinyl chloride is used as the halogenated vinyl polymer. The film is stretched in a stretching ratio of more than 1.2 times the length without break, pre-ferably 2 to 8.5 times. Optionally, the film may be also stretched in a direction at right angle to the above stretching direction in a stretching rat~o of about 1.1 to 2 times the length after, before or at the same time as the above stretching in order to improve the mechanical properties of the film.
The light-polarizing film of the present invention thus obtained has very good heat stahility compared to a conventional polyene-containing light-polarizing film ~.23~3~
containing no acrylate or methacrylate polymer. That is, the light-polarizing film of the present invention can be used for a long time under dry or wet heating conditions, such as at 40 to 30C, with minimum change of polarization efficiency and color ~hue and density). Accordingly, the `light-polarizing film of the present invention can be used without any trouble even in those applications where a light-polarizing film (or a device using a light-polarizing film) hitherto could not be used due to high temperature and humidity.
Moreover, the light-polarizing film of the present invention is superior in transparency and physical pro-perties to conventional light-polarizing film composed only of a polyene-containing halogenated vinyl or vinylidene polymer since the film of the present invention contains an acrylate or methacrylate polymer having good transparency.
In view of the above characteristics, the light-polarizing film of the present invention can be used in various fields, such as liquid crystal display devices, various optical devices or apparatuses, light-filters in photography, sun glasses, sunvisors and the like.
In practice, the light-polarizlng film of the present invention may be laminated with a protective transparent plastic or glass in order to protect the film from light.
In particular, when the film is used in the open air or in a liquid crystal device, it is preferable to laminate a filter thereto which cuts off the light of under 430 m~
since specific superior light resistance is re~uired.
Provided optical uniformity can be maintained, the filter to be laminated may be any layer or film which can .. . . .. ,:, ... . .
3~o~
be formed on the surface of the light-polarizing film of the present invention, for example, a protective plastic plate or film which is formed on the light-polarizing film, a coating layer which is coated on the light-polarizing film or an adhesive layer which is provided between a protective film and the light-polarizing film.
As a base material of the layer or film, various general purpose polymers, preferably, those having superior transparency, such as cellulose acetate, cellulose butyrate, cellulose acetate butyrate, polycarbonate and polyvinyl acrylate, can be used. Also, a urethane resin, an epoxy resin, polybutyl acrylate or polybutyl meth-acrylate can be used as the adhesive for the lamination.
Such a protective filter can be prepared from the above polymer in the following manner. A film or sheet formed from the base polymer is treated in a mixture of a yellow dye having a maximum light absorption around 400 m~
and a UV àbsorber at a temperature of from room tempera-ture to the softening point of the polymer for several seconds to several tens of minutes, washed with water (or the solvent is removed), and then air-dried. Alterna-tiv~ly, a mixture of the polymer, the above yellow dye and ~the UV absorber may be formed into a film or a sheet, or the mixture may be coated on the surface of the light-polarizing film to form a coating film. Further, the yellow dye and the UV absorber may be admixed in the above adhesive between the light-polarizing film and a protective film thereon. Examples of a yellow dye having a maximum light absorption around 400 m~ are a disperse dye such as C.I. Disperse Yellow 5, C.I. Disperse Yellow 8 and the like and an acidic dye such as C~I. Direct .
3~;3,~
Yellow 29, C.I. Direct Yellow 69 and the like. Examples of the UV absorber are 2,2'-dimethoxybenzophenone/
2,2'-414'-tetrahydroxybenzophenone, 2-(2-hydroxy-5-methyl-phenyl)-benzotriazole and the like. When the above polymer is treated in the form of a film or a sheet, a mixture comprising 0.1 to 5 parts by weight of the yellow dye and 0.1 to 10 parts by weight of the UV absorber per 100 parts by weight of a solvent (e.g. methyl ethyl ketone, ethyl acetate etc.) is preferably used for the treatment. When a mixture of the polymer, the yellow dye and the UV absorber is formed into a film or is coated on the light-polarizing film, a suitable amount of the yellow dye is in the range of 0.05 to 5 parts by weight per 100 parts by weight of the polymer, although the amount varies with the thickness of the film or coating film to be formed or the adhesive layer.
The filter thus obtained may be provided on both surfaces of the light-polarizing film of the present invention, but, usually, it is sufficient to provide it on only one surface of the light-polarizing film. The light-polarizing film laminated with the filter can be used in such a mariner that incident light can reach the light-polarizing film only through the filter.
The following Examples illustrate the present inven-tion wherein the parts are by weight. In the Examples, the heat stability of the light-polarizing film is eval-uated by the degree of (1) change in light transmittance (k) at the wavelength of 590 m~ ) change in the maximum absorption wavelength (~ max)~ and (3) change in the dif-ference between ~0 and Hgo (QH - Ho - Hgo) at the wavelength of 400 to 700 m~ (calculated ~rom EIo and ~.23~;3~
Hgo measured within the wavelength range at intervals of 10 m~) before and after a continuous use of the film under dry heating conditions (the degree of these changes is smaller, the change in polarization efficiency is lesser and the change i~ color is also lesser).
The light transmittance was measured with respect to a sheet of the sample film by Beckman DB-G photoelectric spectrophotometer according to the standard method.
Example 1 A commercially available polyvinyl chloride ~4 parts, average polymerization degree: 1,800) was dissolved in dimethylformamide (25 parts). To this solution was added trimethylamine (0.7 part) and reacted at 80C for 200 minutes.
After the completion of the reaction, a commercially avail-able polymethyl methacrylate (2 parts, average polymerization degree: 1,800) was added to the reaction mixture. The resulting solution was cast on a glass plate and treated at 80C for 5 hours to evapolate the solvent to obtain a trans-parent ~ilm of 30~ in thickness. The film was heated at 90C for 15 hours to obtain a bluish violet transparent film. The film was stretched 5.5 times the length in one direction to obtain a light-polarizing film. For a com-parative purpose, a light-polarizing film was prepared according to the same procedure except that polyvinyl chlo-ride (2 parts) was substituted for the polymethyl methacry-late (comparative example).
These light-polarizing films were treated by dry heating at 70C for 3 daysO The change in optical pro-perties of the each film is shown in Table 1.
35~
Table 1 . s . . . . .. . ... . . ....... . :, Sample Before heat treatment After heat treatment _~ . . .
k ~max Average k ~max Average (%) (m~) ~ (%) (%) (m~) ~H (~) . ___ . . .
Example 1 55 590 12 54 585 12 Compara-tive 56 590 11 35 555 6 Example E~
A commercially available polyvinyl chloride (5 parts, average polymerization degree: 2,500) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetrahydrofuran (15 parts). To this solution was added 1,8-diazabicyclo[5.4.0]undecene~7 (0.05 part) and partially dehydrohalogenated at 60C for 30 minutes.
Separately, a commercially available polymethyl methacrylate (5 parts, avera~e polymerization degree: 1,800) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetrahydrofuran (15 parts).
The solution of polymethyl methacrylate (PMMA) and the above prepared reaction mixture was mixed in various ratios and further added thereto a mixed solvent of di-methylformamide and tetrabydrofurane (1:1) in such an amount as the solid content of the mixture is 5 ~.by weight.
The mixture was cast on a glass place and evapolated the solvent to obtain a yellow transparent film of 40~ in thick-ness. The film was heated at 90C for 1 hour to obtain a bluish violet transparent film. The film was then stretched ~.23~
6 times the length in one direction at 110C to obtain valious light-polarizing films.
The above obtained 6 light-polarizing films of various P~A contents were treated by dry heating at 70C
for 3 days. The change in optical properties of the each film is shown in Table 2.
Table 2 PMMA Before heat treatment ¦ After heat treatment content (wt %) __ _ _ k ~ max Average k ~max Average (~5) (m~) ~H (%) (%) (m~) ~H (%) 57 ~ ~ 10-~ ~ 31 555 ~ 4 ~--! 30 58 ~ 590 1056 585 10 56 1 590 _ 55 1 585 _ Example 3 A solution of partially dehydrohalogenated poly~
vinyl chloride prepared by the same procedure in Example 2 was mixed with a solution of various polyalkyl methacrylates ( the concentration and the solvent are the same as those of PMMA solution in Example 2) in such a ratio as the amount of the polyalkyl methacrylat~ is 20 % by weight based on the total amount of the resins in the mixture obtained. The mixture was cast on a glass plate and evapolated the solvent to obtain a film of 50ll in thickness. The film was heated at 90C for 2 hours. The bluish violet film thus obtained ' ~ ~
3~3~
was then stretched 5.5 times the length in one direction at 110C to obtain valious light-polarizing films.
The above obtained light-polarizing films con-taining various polyalkyl methacrylates and a light-pola-rizing film prepared for a comparative purpose by the same procedure without addition of any polyalkyl methacrylate were treated by dry heating at 70C for 3 days. The change in optical properties of the each film is shown in Table 3.
The alphabetical numbers of the polymers in Table 3 mean as follows (the numbers in parenthesis are molar ratios of copolymerization):
A : polyethyl methacrylate, B : polybutyl methacrylate, C : copoly(methyl methacrylate-ethyl methacrylate) (70/30), D : copoly(methyl methacrylate-methyl acrylate) (80/20), and E : copoly(methyl methacrylate-ethyl acrylate) (60/40).
Tab3.e 3 ..... __ __._ . . . ............. .. _._ __ . 7 Polymer Before heat treatment After heat treatment ¦
added k Amax ¦ Average k ¦ Amax ¦ Average ¦ (%) (m~ H (%) (%) ¦ (m~QH (%) - -- --- ~ - - . ~, _ Non 52 ¦ 590 1 8 23¦ 555 3 j 1 52 ', 590 1 9 47¦ 585 19 54 ~ 590 ¦11 49¦ 580 10 ~ , C1 53 , 590 i10 511 585 9 D¦ 50 590 i 8 47585 8 .
E¦ 51 i 590 ~l9 48585 9 ~ ---- t '~`, '.
'il-- ---- ' - - _ _ . . _ _ _. _ , -3~3~
Exam~le 4 A commercially available polyvinyl chloride (5 parts, average polymerization degree: 2,500) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetra-hydrofuran (15 parts). To this solution was added 1.8- -diazabicyclo[5.4.0]undecene-7 (0.05 part) and partially dehydrohalogenated at 60C for 30 minutes.
Separately, polyisobornyl methacrylate (5 parts, average polymerization degree: 1,500) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetra-hydrofuran (15 parts).
The above prepared reaction mixture and the solution of polyisobornyl methacrylate (PIBA) was mixed in the weight ratio of solid content of 8/2 and further added thereto a mixed solvent of dimethylformamide and tetra-hydrofuran (1 : 1) in such an amount as the solid content o~
the mixture is 1 ~ by weight. The mixture was cast on a glass plate and evapolated the solvent to obtain a yellow transparent film of 40~ in thickness. The film was heated at 90C for 70 minutes to obtain a bluish violet transparent ~ilm. The film was then stretched 6 times the length in one direction at I10C to obtain a light-polarizing film.
The light-polarizing film was treated by dry heating at 70C for 5 days. The change in optical pro-perties of the film is shown in Table 4.
"~, __... . . . .
' Table 4 . ... _ _ .
PIBA Before heat treatment After heat treatment content ~ (wt %) . . . ---~ - ---r ----- -------------k ~max Average k ~max IAverage Color (%) (m~) QH (%) (~) (m~ ~1 (%) differ-i ence (~E) _ .. . . __ .. _ !
0 51 590 11 .1 29 1 555 5 8.0 S0 590 ~ 11 1.3 ~:
'' ' ' , ' ~ ~
:
~ ' , , -.
. .
.: .
:
-.
.~,~_....... .. __ _ _ .. . . . . . . . .. . ___ ~
or a cycloalkyl ~ro-lp or bicycloalkyl group having ~ to 10 carbon atoms (e.g. cyclohexyl, etc.), a heterocyclic group having one or more hetero a~oms selected grom O, N and S
(e.g. furfuryl, thienyl etc.), -CN, -OH or -OOCR5; R5 is an alkyl group having 1 to 10 carbon atoms and the alkyl chain of the groups R4 and R5 may be interrupted with O, N, S, or -COO- and the group R4 may be substi-tuted with one or more OH or halogens (e.g. bromine, etc.).
Examples of the acrylate or methacrylate polymer are homopolymers such as polymethyl methacrylate, polyethy methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethyl acrylate and the like; bipolymers such as methyl methacrylate-ethyl methacrylate copolymer, methyl methacrylate-propyl methacrylate copolymer, methyl methacry-late-butyl methacrylate copolymer, ethyl methacrylate-propyl methacrylate copolymer, methyl methacrylate-methyl acrylate copolymer, ethyl methacrylate-methyl acrylate copolymer, ; methyl methacrylate-ethyl acrylate copolymer, methyl acrylate-methyltri~lycol acrylate copolymer, methyl methacrylate-methyltriglycol acrylate copolymer, methyl methacrylate-stearyl acrylate copolymer, methyl methacrylate-stearyl methacrylate copolymer, ethyl methacrylate-ethy acrylate copolymer, methyl methacryla-te-butyl acrylate copolymer, methyl methacrylate-propyl acrylate copolymer, methyl methacrylate-2-hydroxyethyl methacrylate copolymer, methyl methacrylate-2-hydroxypropyl methacrylate copolymer, ethyl methacrylate-2-hydroxyethyl methacrylate copolymer, ethyl methacrylate-2-hydroxypropyl methacrylate copolymer,methyl - " ~h~.~;3~3~
ethacrylate-2-hydroxyethyl acrylate copolymer, methyl methacrylate-2-hydroxypropyl acrylate copolymer, ethyl methacrylate-2-hydroxyethyl acrylate copolymer, ethyl meth-acrylate-2-hydro~ypropyl acrylate copolymer, methyl meth-acrylate-tetrahydrofurfuryl acrylate copolymer, methyl methacrylate-tetrahydro~urfuryl methacrylate copolymer, ethyl methacrylate-tetrahydrofurfuryl acrylate copolymer, ethyl me~hacrylate tetrahydrofurfuryl methacrylate copolymer, methyl methacrylate-benzyl acrylate copolymer, methyl methacrylate-benzyl methacrylate copolymer, methyl meth-acrylate-benzyl acrylate copolymer, methyl methacrylate- : ;
phenoxyethyl acrylate copolymer, methyl methacrylate-phenoxy-ethyl methacrylate copolymer, methyl methacrylate-cyclohexyl acrylate copolymer, methyl methacrylate-cyclohexyl meth-acrylate copolymer, methyl methacrylate-glycidyl acrylate copolymer, methyl methacrylate-ylycidyl methacrylate copolymer, ethyl methacrylate-tribromophenyl acrylate copolymer methyl methacrylate-dibromopropyl acrylate copolymer, methyl methacrylate-tropine acrylate copolyme~, methyl methacry-late-tropine methacrylate copolymer, methyl acrylate-tropine methacrylate copolymer, ethyl methacrylate-tropine acrylate copolymer, methyl methacrylate-isobornyl methacrylate co-polymer, methyl methacrylate-isobornyl acrylate copolymer, ethyl methacrylate-isobornyl methacrylate copolymer, propyl methacrylate-isobornyl methacrylate copolymer, methyl methacrylate-lsomenthyl acrylate copolymer, metyl meth-acrylate~isomenthyl methacrylate copolymer, ethyl meth-acrylate~isomenthyl methacrylate copolymer,methyl acrylate~
:~ acrylonitrile copolymer, butyl acrylate-acrylonitrile copolymer, n~propyl acrylate~acrylonitrile copolymer and the like; and terpolymers such as methy methacrylate~ethyl methacrylate~
~ 8 ~
3~
butyl Methacrylate copolymer, methyl methacrylate-ethyl methacrylate-methyl acrylate copolymer, methyl methacrylate-ethyl methacrylate methyltriglycol acrylate copolymer, methyl methacrylate-ethyl methacrylate-stearyl acrylate co-polymer, methyl methacrylate-ethyl methacrylate-stearyl methacrylate copolymer, methyl methacrylate-ethyl meth-acrylate-tetrahydrofurfuryl acrylate copolymer, methyl methacrylate-ethyl methacrylate-tetrahydrofurfuryl meth-acrylate copolymer, methyl methacrylate-ethyl methacrylate-benzyl acrylate copolymer, methyl methacrylate-ethyl meth-acrylate-benzyl methacrylate copolymer, methyl methacrylate-ethyl methacrylate-phenoxyethyl acrylate copolymer, methyl methacrylate-ethyl methacrylate-phenoxyethyl methacrylate copolymer, methyl methacrylate-ethyl methacrylate-cyclo-hexyl acrylate copolymer, methyl methacrylate-ethyl meth-acrylate-cyclohexyl methacrylate copolymer, methyl meth-acrylate-ethyl methacrylate-glycidyl acrylate copolymer, methyl methacrylate-ethyl methacrylate-glycidyl methacrylate copolymer, methy methacrylate-ethyl me~thacrylate-tribromo-phenyl acrylate copolymer, methyl methacrylate-ethyl meth-acrylate-tribromophenyl methacrylate copolymer, ~ethyl methacrylate-ethyl methacrylate-dibromophenyl methacrylate copolymer, methyl methacryla-te-methyl acrylate-benzyl meth- :
acrylate copolymer, methyl methacrylate~methyl acrylate-cyclohexyl acrylate copolymer, methyl methacrylate-methyl acrylate-~lycidyl methacrylate copolymer, methyl methacry-late-methyl acrylate-tribromophenyl methacrylate copolymer and the like. These polymers can be used alone or in any combination thereof.
Preferably, the acrylate or methacrylate polymer is used in an amount of 5 to 95 % by weight, more preferably 3~3:~
5 to 35 ~ by weight, based on the total weight of the halogenated vinyl or vinylidene polymer used for the formation of polyene chains. When the amount of the polymer is less than 5 ~ by weight, the improvement in heat stability of the resulting light-polarizing film is low. On the other hand, when the amount of the polymer is more than 95 ~ by weight, the polyene concentration in the molecule is insufficient and the polarization efficiency is lowered.
The halogenated vinyl or vinylidene polymer used for the formation of polyene chains is preferably a homo- ~ ;
polymer or a copolymer of a monomer of the formula:
/R6 `~ ~ ~
CH2 = C \ (III) X
in which X is halogen (preferably, chlorine or bromine);
R6 is hydrogen, -CN, -COOR7, -OOCR8 or an aryl group having 6 to 10 carbon atoms (e.g phenyl, naphthyl, etc.);
R7 is an alkyl group having 1 to 10 carbon atoms; and R8 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.) or a cycloalkyl ~roup having 5 to 10 carbon atoms (e.g. cyclohexyl, etc.).
Typical examples of these polymers are a homopolymer ; or a copolymer of a vinyl halide and/or a vinylidene haIide such as vinyl chloride, vinyl bromide, vinylidene chloride and the like.
Further, the halogenated vinyl or vinylidene polymer -:
may include a copolymer of the above monomer (III) and up to 90 mol % (based on all the structural units of the polymer) of another copolymerizable monomer, preferably, .
3~
a monomer of the formula:
/
C~2 = C (IV) in ~hich Rg is hydrogen or an alkyl group having 1 to 10 carbon atoms; Rlo is hydrogen, a hydrocarbon group having 1 to 10 carbon atoms such as an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.) or a cycloalkyl groùp having 5 to 10 carbon atoms (e.g. cyclohexyl, etc.), a heterocyclic group having one or more hetero atoms sel-ected from O, N and S (e.g. furfuryl, thienyl etc.), -CN, -COORll, -OOCR12 or -OH; Rll is hydrogen or an alkyl group having 1 to 10 carbon atoms; R12 is an alkyl group having 1 to lQ carbon atoms, an aryl group having 6 to 10 carbon atoms (e.g. phenyl, naphthyl, etc.), or a cyclo-alkyl group having 5 to 10 carbon atoms (e.g. cyclohexyl etc.) and the alkyl chain of the groups Rll and R12 may be interrupted with O, N or S and the hydrocarbon group of Rlo may be substituted with one or more halogens.
When using a copolymer of a vinyl halide and a vinyli-dene halide and/or one or more other copolymerizable monomers, the copolymer must be in the form of a block copolymer or a graft copolymer so as to form polyene chains having suffisient chain length and it is preferable that the average chain length (polymeriæation degree) of a polyv~nyl halide block or a polyvinylidene halide block in the copolymer is more than 20. When the chain length is less than 20, it is difficult to obtain light-polarizing elements having sufficient activity within the visible ;~
:
.. :
light range. Further, it is preferable that the molar ratio of a vinyl halide or a vinylidene halide to all structural units of the polymer is 0.1/1 to 1/1, more preferably 0.5/1 to 1/1.
Examples of suitable block copolymers are as follows (they are shown by monomer structural units wherein "VC"
and "VB" stand for vinyl chloride and vinyl bromide, respectively):
VC-vinyl acetate, VC-acrylonitrile, VC-ethylene, VC-pro-pylene, VC-styrene, VC-butadiene, VC-isoprene, VC-vinyli-dene chloride, VC-acrylic acid, VC-methyl acrylate, VC-methyl methacrylate, VC-ethylene trifluoride, VB-vinyl acetate, VB-acrylonitrile, VB-ethylene, VB-propylene, VB-vinylidene chl~ride, VB-styrene, VB-acrylic acid, VB-methyl acrylate, VB-methyl methacrylate, VC-vinyl acetate-vinyl alcohol, VC-vinylidene chloride-methyl acrylate, VC-vinyl ~luoride-ethylene tetrafluoride, VB-styrene-methyl acrylate, ~-chlorovinylbenzene-vinylbenæene, ~-chloro-acrylonitrile-acrylonitrile, ~-chloroacrylonitrile-meth-acrylic acid. Suitable examples of the graft copolymerare polyvinyl chloride graft-copolymerized with methyl methacrylate or styrene, polyvinyl bromide graft-copoly-merized wlth styrene and the like.
These polymers or copolymers capable of formation of polyene chains can be used alone or in any combination thereof.
The light-polarizing film of the present invention preferably contains 5 to 95 ~ by weight of the acrylate or methacrylate polymer and 5 to 95 ~ by weight of the partially dehydrohalogenated halogenated vinyl or vinyli-dene polymer.
' ' If desired, one or more other film-forming polymers can be present in the light-polarizing film of the present invention together with the polymer having polyene chains and the acrylate or methacrylate polymer. Examples of these polymers are polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl aceta-te-vinyl alcohol copolymer, vinyl acetate-vinyl alcohol copolymer.
As described above, the formation of polyene chains can be carried out in one step with a dehydrohalogenating agent alone, or in two steps with a dehydydrohalogenating agent and then a heat treatment.
The dehydrohalogenating agent used in the present invention is, for example, a secondary or tertiary amine such as triethylamine, tri-n-propylamine, tri-n-butyl-amine, tri~n-amylamine, triethylened;aminediethylamine, di-n-propylamine and di-n-butylamine; an alkali metal alcoholate such as sodium methylate and sodium ethylate;
an amidine compound such as 1,8-diazabicyclol5.4.0]un-decene-7 and 1,5-diazabicyclo[4.3.0]nonene-5 and the like.
Although the preferred amount of the dehydrohalogen-ating agent depends upon the content of the partially dehydrohalogenated halogenated vinyl or vinylidene polymer and other polymer in the film, it is desirable to use more than 0.1 part by weight of the dehydrohalogenating agent per lO0 parts by weight of the halogenated vinyl or vinyli-dene polymer. When the amount of the dehydrohalogenating agent is less than 0.1 part by weight, the reaction rate is extremely low.
The dehydrogenation can be carried out in respect of 3~;3~
the polymer in the form of a solution or solid as described above.
The solvent which dissolves the polymer to be used and the dehydrohalogenating agent and is suitable for carrying out the dehydrohalogenation is, for example, dimethylformamide, diethylformamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, methyl ethyl ketone, a mixture thereof and the like.
When the dehydrohalogenation is carried out in the form of a solution, the dehydrohalogenating agent is desirably added to the polymer dissolved in the above solvent in an amount of 0.00001 to 1 mol ~, preferably 0.00002 to 0.4 mol %, based on the amount of the vinyl halide or vinylidene halide units in the polymer to be used.
When the dehydrohalogenation is carried out in the form of solid such as a film, the material to be dehydro-halogenated is treated with a solution o~ the dehydro-halogenating agent (concentration: 1 to 50 % by weight) in a good solvent thereof which does not dissolve the material (usually, n-hexane, n-heptane, isopropyl ether and the like can be used).
When forming the polyene chains in two steps, the treatment with the dehydrohalogenating agent is usually carried out at 5 to 150C, preferably at 20 to 100C, until the dehydrohalogenation degree reaches 0.1 to 20 mol ~, preEerably 0.2 to 10 mol %. The dehydrohalogen-ation degree can be calculated by the change of halogen content of the polymer used but the progress of the dehydrohalogenation can also be fairly exactly checked by the color change of the polymer or a solution thereof.
3~
That is, when the dehydrohalogenation is adequately carried out, the product has a yellow color whereas the product becomes orange, red or black when excess dehydro-halogenation takes place. Accordingly, the time when the reaction should be stopped can usually be decided by mon-itoring the change of the visible light transmittance curve of the reaction mixture to check the progress of the reac-tion (light absorption is initially observed in the near UV
range and gradually appears in a longer wavelength range).
In the molecule of the polymer thus partially dehydro-halogenated by the dehydrohalogenating agent, double bonds are distributed at random and polyene chains having short chain length are also partially formed. When the polymer is subsequently treated by heating, the growth of the polyene chains is initiated at these double bonds.
The heat treatment o~ the above deh~drohalogenated product is carried out in air or in an inert gas such as nitrogen at 50 to 150C, preferably at 60 to 130C, under atmospheric pressure or a reduced pressure.
During the heat treatment, the polyene chains grow with the progress of the treatment since the reaction is a chain reaction initiated at the double bonds which are ~ ;
already present in the molecule of the polymer. With the growth of the polyene chains, the light absorption of the reaction product within the visible light range increases and the color thereof changes to blue via violet.
~hen the reaction mixture is a blue color, its visible light transmittance curve shows a maximum absorption at wavelengths of 565 to 600 m~. Therefore, the heat treat-ment is preferably terminated when a maximum absorption of the reaction mixture is observed within or at least around ~ ~;3~3~
the abo~e wavelength and the light transmittance thereof at the wavelength of the maximum absorption reaches 0.001 to 60 ~, preferably 0.01 to 45 %. At this stage, 10 to 25 double bonds are linked in the polyene chains.
The heat treatment time necessary for the formation of polyene chains having sufficient length varies with the dehydrohalogenation degree (in the above treatment with the dehydrohalogenating agent) and other conditions but, usually, it is in the range of 2 minutes to 20 hours.
In any process, the polymer is dehydrohalogenated until the dehydrohalogenation degree finally reaches 0.1 to 30 mol %, usually 0.5 to 20 mol %.
After the dehydrohalogenation, the polyene chains formed in the polyvinyl or vinylidene halide are uni-directionally orientated by stretching a film formed from a polymer mi~ture comprising, as the main compounds, the polymer having polyene chains and the acrylate or meth-acrylate polymer. The stretching is carried out, for example, at 80 to 150C, preferably at 85 to 1~0C, when polyvinyl chloride is used as the halogenated vinyl polymer. The film is stretched in a stretching ratio of more than 1.2 times the length without break, pre-ferably 2 to 8.5 times. Optionally, the film may be also stretched in a direction at right angle to the above stretching direction in a stretching rat~o of about 1.1 to 2 times the length after, before or at the same time as the above stretching in order to improve the mechanical properties of the film.
The light-polarizing film of the present invention thus obtained has very good heat stahility compared to a conventional polyene-containing light-polarizing film ~.23~3~
containing no acrylate or methacrylate polymer. That is, the light-polarizing film of the present invention can be used for a long time under dry or wet heating conditions, such as at 40 to 30C, with minimum change of polarization efficiency and color ~hue and density). Accordingly, the `light-polarizing film of the present invention can be used without any trouble even in those applications where a light-polarizing film (or a device using a light-polarizing film) hitherto could not be used due to high temperature and humidity.
Moreover, the light-polarizing film of the present invention is superior in transparency and physical pro-perties to conventional light-polarizing film composed only of a polyene-containing halogenated vinyl or vinylidene polymer since the film of the present invention contains an acrylate or methacrylate polymer having good transparency.
In view of the above characteristics, the light-polarizing film of the present invention can be used in various fields, such as liquid crystal display devices, various optical devices or apparatuses, light-filters in photography, sun glasses, sunvisors and the like.
In practice, the light-polarizlng film of the present invention may be laminated with a protective transparent plastic or glass in order to protect the film from light.
In particular, when the film is used in the open air or in a liquid crystal device, it is preferable to laminate a filter thereto which cuts off the light of under 430 m~
since specific superior light resistance is re~uired.
Provided optical uniformity can be maintained, the filter to be laminated may be any layer or film which can .. . . .. ,:, ... . .
3~o~
be formed on the surface of the light-polarizing film of the present invention, for example, a protective plastic plate or film which is formed on the light-polarizing film, a coating layer which is coated on the light-polarizing film or an adhesive layer which is provided between a protective film and the light-polarizing film.
As a base material of the layer or film, various general purpose polymers, preferably, those having superior transparency, such as cellulose acetate, cellulose butyrate, cellulose acetate butyrate, polycarbonate and polyvinyl acrylate, can be used. Also, a urethane resin, an epoxy resin, polybutyl acrylate or polybutyl meth-acrylate can be used as the adhesive for the lamination.
Such a protective filter can be prepared from the above polymer in the following manner. A film or sheet formed from the base polymer is treated in a mixture of a yellow dye having a maximum light absorption around 400 m~
and a UV àbsorber at a temperature of from room tempera-ture to the softening point of the polymer for several seconds to several tens of minutes, washed with water (or the solvent is removed), and then air-dried. Alterna-tiv~ly, a mixture of the polymer, the above yellow dye and ~the UV absorber may be formed into a film or a sheet, or the mixture may be coated on the surface of the light-polarizing film to form a coating film. Further, the yellow dye and the UV absorber may be admixed in the above adhesive between the light-polarizing film and a protective film thereon. Examples of a yellow dye having a maximum light absorption around 400 m~ are a disperse dye such as C.I. Disperse Yellow 5, C.I. Disperse Yellow 8 and the like and an acidic dye such as C~I. Direct .
3~;3,~
Yellow 29, C.I. Direct Yellow 69 and the like. Examples of the UV absorber are 2,2'-dimethoxybenzophenone/
2,2'-414'-tetrahydroxybenzophenone, 2-(2-hydroxy-5-methyl-phenyl)-benzotriazole and the like. When the above polymer is treated in the form of a film or a sheet, a mixture comprising 0.1 to 5 parts by weight of the yellow dye and 0.1 to 10 parts by weight of the UV absorber per 100 parts by weight of a solvent (e.g. methyl ethyl ketone, ethyl acetate etc.) is preferably used for the treatment. When a mixture of the polymer, the yellow dye and the UV absorber is formed into a film or is coated on the light-polarizing film, a suitable amount of the yellow dye is in the range of 0.05 to 5 parts by weight per 100 parts by weight of the polymer, although the amount varies with the thickness of the film or coating film to be formed or the adhesive layer.
The filter thus obtained may be provided on both surfaces of the light-polarizing film of the present invention, but, usually, it is sufficient to provide it on only one surface of the light-polarizing film. The light-polarizing film laminated with the filter can be used in such a mariner that incident light can reach the light-polarizing film only through the filter.
The following Examples illustrate the present inven-tion wherein the parts are by weight. In the Examples, the heat stability of the light-polarizing film is eval-uated by the degree of (1) change in light transmittance (k) at the wavelength of 590 m~ ) change in the maximum absorption wavelength (~ max)~ and (3) change in the dif-ference between ~0 and Hgo (QH - Ho - Hgo) at the wavelength of 400 to 700 m~ (calculated ~rom EIo and ~.23~;3~
Hgo measured within the wavelength range at intervals of 10 m~) before and after a continuous use of the film under dry heating conditions (the degree of these changes is smaller, the change in polarization efficiency is lesser and the change i~ color is also lesser).
The light transmittance was measured with respect to a sheet of the sample film by Beckman DB-G photoelectric spectrophotometer according to the standard method.
Example 1 A commercially available polyvinyl chloride ~4 parts, average polymerization degree: 1,800) was dissolved in dimethylformamide (25 parts). To this solution was added trimethylamine (0.7 part) and reacted at 80C for 200 minutes.
After the completion of the reaction, a commercially avail-able polymethyl methacrylate (2 parts, average polymerization degree: 1,800) was added to the reaction mixture. The resulting solution was cast on a glass plate and treated at 80C for 5 hours to evapolate the solvent to obtain a trans-parent ~ilm of 30~ in thickness. The film was heated at 90C for 15 hours to obtain a bluish violet transparent film. The film was stretched 5.5 times the length in one direction to obtain a light-polarizing film. For a com-parative purpose, a light-polarizing film was prepared according to the same procedure except that polyvinyl chlo-ride (2 parts) was substituted for the polymethyl methacry-late (comparative example).
These light-polarizing films were treated by dry heating at 70C for 3 daysO The change in optical pro-perties of the each film is shown in Table 1.
35~
Table 1 . s . . . . .. . ... . . ....... . :, Sample Before heat treatment After heat treatment _~ . . .
k ~max Average k ~max Average (%) (m~) ~ (%) (%) (m~) ~H (~) . ___ . . .
Example 1 55 590 12 54 585 12 Compara-tive 56 590 11 35 555 6 Example E~
A commercially available polyvinyl chloride (5 parts, average polymerization degree: 2,500) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetrahydrofuran (15 parts). To this solution was added 1,8-diazabicyclo[5.4.0]undecene~7 (0.05 part) and partially dehydrohalogenated at 60C for 30 minutes.
Separately, a commercially available polymethyl methacrylate (5 parts, avera~e polymerization degree: 1,800) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetrahydrofuran (15 parts).
The solution of polymethyl methacrylate (PMMA) and the above prepared reaction mixture was mixed in various ratios and further added thereto a mixed solvent of di-methylformamide and tetrabydrofurane (1:1) in such an amount as the solid content of the mixture is 5 ~.by weight.
The mixture was cast on a glass place and evapolated the solvent to obtain a yellow transparent film of 40~ in thick-ness. The film was heated at 90C for 1 hour to obtain a bluish violet transparent film. The film was then stretched ~.23~
6 times the length in one direction at 110C to obtain valious light-polarizing films.
The above obtained 6 light-polarizing films of various P~A contents were treated by dry heating at 70C
for 3 days. The change in optical properties of the each film is shown in Table 2.
Table 2 PMMA Before heat treatment ¦ After heat treatment content (wt %) __ _ _ k ~ max Average k ~max Average (~5) (m~) ~H (%) (%) (m~) ~H (%) 57 ~ ~ 10-~ ~ 31 555 ~ 4 ~--! 30 58 ~ 590 1056 585 10 56 1 590 _ 55 1 585 _ Example 3 A solution of partially dehydrohalogenated poly~
vinyl chloride prepared by the same procedure in Example 2 was mixed with a solution of various polyalkyl methacrylates ( the concentration and the solvent are the same as those of PMMA solution in Example 2) in such a ratio as the amount of the polyalkyl methacrylat~ is 20 % by weight based on the total amount of the resins in the mixture obtained. The mixture was cast on a glass plate and evapolated the solvent to obtain a film of 50ll in thickness. The film was heated at 90C for 2 hours. The bluish violet film thus obtained ' ~ ~
3~3~
was then stretched 5.5 times the length in one direction at 110C to obtain valious light-polarizing films.
The above obtained light-polarizing films con-taining various polyalkyl methacrylates and a light-pola-rizing film prepared for a comparative purpose by the same procedure without addition of any polyalkyl methacrylate were treated by dry heating at 70C for 3 days. The change in optical properties of the each film is shown in Table 3.
The alphabetical numbers of the polymers in Table 3 mean as follows (the numbers in parenthesis are molar ratios of copolymerization):
A : polyethyl methacrylate, B : polybutyl methacrylate, C : copoly(methyl methacrylate-ethyl methacrylate) (70/30), D : copoly(methyl methacrylate-methyl acrylate) (80/20), and E : copoly(methyl methacrylate-ethyl acrylate) (60/40).
Tab3.e 3 ..... __ __._ . . . ............. .. _._ __ . 7 Polymer Before heat treatment After heat treatment ¦
added k Amax ¦ Average k ¦ Amax ¦ Average ¦ (%) (m~ H (%) (%) ¦ (m~QH (%) - -- --- ~ - - . ~, _ Non 52 ¦ 590 1 8 23¦ 555 3 j 1 52 ', 590 1 9 47¦ 585 19 54 ~ 590 ¦11 49¦ 580 10 ~ , C1 53 , 590 i10 511 585 9 D¦ 50 590 i 8 47585 8 .
E¦ 51 i 590 ~l9 48585 9 ~ ---- t '~`, '.
'il-- ---- ' - - _ _ . . _ _ _. _ , -3~3~
Exam~le 4 A commercially available polyvinyl chloride (5 parts, average polymerization degree: 2,500) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetra-hydrofuran (15 parts). To this solution was added 1.8- -diazabicyclo[5.4.0]undecene-7 (0.05 part) and partially dehydrohalogenated at 60C for 30 minutes.
Separately, polyisobornyl methacrylate (5 parts, average polymerization degree: 1,500) was dissolved in a mixed solvent of dimethylformamide (15 parts) and tetra-hydrofuran (15 parts).
The above prepared reaction mixture and the solution of polyisobornyl methacrylate (PIBA) was mixed in the weight ratio of solid content of 8/2 and further added thereto a mixed solvent of dimethylformamide and tetra-hydrofuran (1 : 1) in such an amount as the solid content o~
the mixture is 1 ~ by weight. The mixture was cast on a glass plate and evapolated the solvent to obtain a yellow transparent film of 40~ in thickness. The film was heated at 90C for 70 minutes to obtain a bluish violet transparent ~ilm. The film was then stretched 6 times the length in one direction at I10C to obtain a light-polarizing film.
The light-polarizing film was treated by dry heating at 70C for 5 days. The change in optical pro-perties of the film is shown in Table 4.
"~, __... . . . .
' Table 4 . ... _ _ .
PIBA Before heat treatment After heat treatment content ~ (wt %) . . . ---~ - ---r ----- -------------k ~max Average k ~max IAverage Color (%) (m~) QH (%) (~) (m~ ~1 (%) differ-i ence (~E) _ .. . . __ .. _ !
0 51 590 11 .1 29 1 555 5 8.0 S0 590 ~ 11 1.3 ~:
'' ' ' , ' ~ ~
:
~ ' , , -.
. .
.: .
:
-.
.~,~_....... .. __ _ _ .. . . . . . . . .. . ___ ~
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A light-polarizing film comprising a polymer mixture of a polymer having polyene chains formed by partial dehydrohalogenation of a halogenated vinyl polymer or a halogenated vinylidene polymer and one or more of the polymers selected from the group consisting of acrylate polymers and methacrylate polymers.
2. A light-polarizing film according to Claim 1, wherein the mixture contains 5 to 95 % by weight of the partial dehydrohalogenated halogenated vinyl or vinylidene polymer and 5 to 95 % by weight of the acrylate or methacrylate polymer.
3. A light-polarizing film according to Claim 1, wherein the film has 10 to 70 % of average light transmittance at the wavelength of 450 to 700 m µ, and wherein the ratio of average percent light transmitted with the polarization axes parallel (H0) to average percent light transmitted with the polarization-axes crossed (H90) of the film is H0/H90?2.
4. A light-polarizing film according to Claim 3, wherein the film has 20 to 70 % of average light transmittance at the wavelength of 450 to 700 mµ, and wherein the ratio of average percent light transmitted with the polarization axes parallel (H0) to average percent light transmitted with the polarization axes crossed (H90) of the film is H0/H90?4.
5. A light-polarizing film according to Claim 1, wherein the acrylate or methacrylate polymer is a homopolymer or a copolymer of a monomer of the formula:
in which R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms; and R2 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or bicycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms or a heterocyclic group containing one or more of hetero atoms selected from O, N and S and the alkyl chain of the group R2 may be interrupted with O, N or S and the alkyl or aryl group may be substituted with one or more of halogens.
in which R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms; and R2 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or bicycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms or a heterocyclic group containing one or more of hetero atoms selected from O, N and S and the alkyl chain of the group R2 may be interrupted with O, N or S and the alkyl or aryl group may be substituted with one or more of halogens.
6. A light-polarizing film according to Claim 1, wherein the acrylate or methacrylate polymer is a copolymer of a monomer of the formula:
in which R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms; and R2 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or bicycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms or a heterocyclic group containing one or more of hetero atoms selected from O, N and S and the alkyl chain of the group R2 may be interrupted with O, N or S and the alkyl or aryl group may be substituted with one or more of halogens and up to 50 mol % based on all the structural units of the polymer of another copolymerizable monomer of the formula:
in which R3 is hydrogen or an alkyl group having 1 to 10 carbon atoms; and R4 is a hydrocarbon group having 1 to 10 carbon atoms, a heterocyclic group having one or more hetero atoms selected from O, N and S, -CN, -OH or -OOCR5; R5 is an alkyl group having 1 to 10 carbon atoms and the alkyl chain of the groups R4 and R5 may be interrupted with O, N, S or -COO- and the group R4 may be substituted with one or more of OH or halogens.
in which R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms; and R2 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl or bicycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms or a heterocyclic group containing one or more of hetero atoms selected from O, N and S and the alkyl chain of the group R2 may be interrupted with O, N or S and the alkyl or aryl group may be substituted with one or more of halogens and up to 50 mol % based on all the structural units of the polymer of another copolymerizable monomer of the formula:
in which R3 is hydrogen or an alkyl group having 1 to 10 carbon atoms; and R4 is a hydrocarbon group having 1 to 10 carbon atoms, a heterocyclic group having one or more hetero atoms selected from O, N and S, -CN, -OH or -OOCR5; R5 is an alkyl group having 1 to 10 carbon atoms and the alkyl chain of the groups R4 and R5 may be interrupted with O, N, S or -COO- and the group R4 may be substituted with one or more of OH or halogens.
7. A light-polarizing film according to Claim 1, wherein the dehydrohalogenation degree of the hydrohalogenated vinyl or vinylidene polymer is 0.1 to 30 mol %.
8. A light-polarizing film according to Claim 1, wherein the halogenated vinyl or vinylidene polymer is a homo-polymer or a copolymer of a monomer of the formula;
in which X is a halogen; R6 is hydrogen, -CN, -COOR7, -OOCR8 or an aryl group having 6 to 10 carbon atoms;
R7 is an alkyl group having 1 to 10 carbon atoms; R8 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms.
in which X is a halogen; R6 is hydrogen, -CN, -COOR7, -OOCR8 or an aryl group having 6 to 10 carbon atoms;
R7 is an alkyl group having 1 to 10 carbon atoms; R8 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms.
9. A light-polarizing film according to Claim 8, wherein said polymer is polyvinyl chloride.
10. A light-polarizing film according to Claim 1, wherein the halogenated vinyl or vinylidene polymer is a block or graft copolymer of a monomer of the formula:
in which X is a halogen; R6 is hydrogen, -CN, -COOR7, -OOCR8 or an aryl group having 6 to 10 carbon atoms;
R7 is an alkyl group having 1 to 10 carbon atoms; R8 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms and up to 90 mol % based on all the structural units of the polymer of another copoly-merizable monomer of the formula:
in which R9 is hydrogen or an alkyl group having 1 to 10 carbon atoms; R10 is hydrogen, a hydrocarbon group having 1 to 10 carbon atoms, a heterocyclic group having one or more hetero atoms selected from O, N and S, -CN, -COOR11, -OOCR12, or -OH; R11 is hydrogen or an alkyl group having 1 to 10 carbon atoms; R12 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms and the alkyl chain of the groups R11 and R12 may be interrupted with O, N or S and the hydro-carbon group of R10 may be substituted with one or more of halogens.
in which X is a halogen; R6 is hydrogen, -CN, -COOR7, -OOCR8 or an aryl group having 6 to 10 carbon atoms;
R7 is an alkyl group having 1 to 10 carbon atoms; R8 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms and up to 90 mol % based on all the structural units of the polymer of another copoly-merizable monomer of the formula:
in which R9 is hydrogen or an alkyl group having 1 to 10 carbon atoms; R10 is hydrogen, a hydrocarbon group having 1 to 10 carbon atoms, a heterocyclic group having one or more hetero atoms selected from O, N and S, -CN, -COOR11, -OOCR12, or -OH; R11 is hydrogen or an alkyl group having 1 to 10 carbon atoms; R12 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms and the alkyl chain of the groups R11 and R12 may be interrupted with O, N or S and the hydro-carbon group of R10 may be substituted with one or more of halogens.
11. A light-polarizing film according to Claim 1, wherein the film is laminated with a filter which cuts off the light of under 430 m µ.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA325,192A CA1123538A (en) | 1979-04-09 | 1979-04-09 | Light-polarizing film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA325,192A CA1123538A (en) | 1979-04-09 | 1979-04-09 | Light-polarizing film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1123538A true CA1123538A (en) | 1982-05-11 |
Family
ID=4113945
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA325,192A Expired CA1123538A (en) | 1979-04-09 | 1979-04-09 | Light-polarizing film |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1123538A (en) |
-
1979
- 1979-04-09 CA CA325,192A patent/CA1123538A/en not_active Expired
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