Facing for plastic foamed construction insulation board

Facings for plastic foamed construction insulation board are made from paper treated with a treatment comprising about 10% to 100% of the weight of the paper including polymer, water repellant, and fire retardant. A reinforcing scrim may be combined with the paper. The treatment is applied to paper, the scrim is combined with the paper, and foam-forming liquids are applied to the paper to form a facing for a plastic foamed construction insulation board.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to facings for use with plastic foamed construction 
insulation boards. These boards are used primarily in roofs and walls, and 
they serve to insulate the interior of buildings from heat and cold. 
2. Description of the Prior Art 
Facings for plastic foamed construction insulation board are located on one 
or both sides of a central plastic foamed core and during manufacture of 
the boards support liquids which are used to create the plastic foam. In 
order to provide a good bond between the facing and the board, it is 
desirable that the liquid flow partially into the facing, but it is also 
important that no foam-forming liquid flow through or "bleed" through the 
facing during manufacturing, inasmuch as that tends to contaminate the 
manufacturing machinery with plastic. 
Between manufacture and installation, and after installation, facings 
provide strength and durability to resist moisture and other damage, which 
can result in loss of insulating properties. In many uses these boards 
must resist substantial stresses such as may result from the lifting 
effect of wind when the boards are installed on roofing. The facing 
material should provide strength to the boards to resist such forces. 
Facings used with insulation boards of the plastic foamed type have 
included metal foils sometimes reinforced with scrim, as shown in U.S. 
Pat. No. 4,073,998 issued to P.M. O'Connor, and mats of glass fibers as 
exemplified by U.S. Pat. Nos. 4,388,366 and 4,414,265, issued to D.W. 
Rosato. Facing materials may also include expanded pearlite boards, metal 
foils, organic felt, heavy papers saturated with 100% or more of their 
weight in asphalt, plywood, hard board, cement-asbestos board, reinforced 
plastic, tempered glass and glass fiber board. Paper alone has not been 
used for this purpose probably because one would expect (i) foam-forming 
liquids to bleed through paper during manufacture of the board, (ii) 
moisture to seep through the paper after manufacture, which could cause 
delamination, (iii) paper to be dangerously flammable, and (iv) paper's 
lack of dimensional stability to cause warped boards. 
SUMMARY OF THE PRESENT INVENTION 
This invention comprises processes for making a facing which is thin, light 
weight, and flexible for use in plastic foamed construction insulation 
boards. It also comprises a facing which includes (a) paper which has been 
treated with a treatment comprising materials, such as a polymer, a water 
repellant, and a flame retardant, whose combined dry weight is about 10% 
to 100% of the weight of the paper and (b) a reinforcing scrim combined 
with the paper. The materials in the treatment of this invention. coat 
fibers in the paper, fill or reduce the size of interstices in the paper, 
and impart to the paper fire retardancy, water repellency, reduced 
porosity and reduced ability to transmit liquids through the fibers of the 
paper, such that foam-forming liquids used in manufacturing the plastic 
foamed construction insulation board do not bleed through the facing 
during manufacture. The paper is provided with sufficient strength and 
durability to be useful for plastic foamed construction insulation board, 
while using lower weight and less expensive components than the prior art. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The facings of this invention may be used with plastic foams of various 
kinds, including urethane, isocyanurate, polystyrene, pheonolic, 
urethane-modified isocyanurate, phenol formaldehyde, urea formaldehyde, 
and melamine formaldehyde foams. 
Papers of various weights and composition may be used in the invention. A 
bleached semi-crepe tissue paper of 20 lbs. (9 kg.) basis weight is 
preferred, and the weight of paper may vary from 10 to 40 lbs. (5 to 18 
kgs.) paper. "Pounds" or "lbs." refer to the number of pounds in 3,000 sq. 
ft. (279 sq. meters) of paper. Preferred papers are less than 5 
mils.(thousandths of an inch) (0.127 mm.) in thickness, and the most 
preferred paper has a thickness of about 3 mils (0.0762 mm.). Such papers 
are significantly less expensive and lighter in weight than materials used 
by the prior art as facings for plastic foamed construction insulation 
board; the treatment as set forth below makes such papers sufficiently 
strong, bleed-through resistant, and durable to be useful as facings for 
such boards while retaining the cost advantages and light weight of thin 
paper. Paper which is made 100% from cellulose material is preferred, but 
non-woven glass continuous filaments or glass staple, or other material 
such as polyester or other synthetic fibers, may also be incorporated into 
the paper, preferably not to exceed 50% by weight of the paper. 
The scrim used in our invention may be made of fiberglass, polyester or 
other equivalent materials. It is preferred to use a non-woven scrim of 
fiberglass coated with polyvinyl alcohol, but other materials may be 
applied to the scrim. The term "scrim" is used to mean an open mesh or net 
fabric of criss-crossed yarns or threads which is woven or non-woven. 
In the most preferred method the paper is bonded to the scrim while the 
polyvinyl alcohol on the scrim is wet, or if the polyvinyl on the scrim 
has previously dried, the scrim is wetted to make the polyvinyl alcohol 
sticky. A preferred polyvinyl alcohol is Dupont's Elvanol dissolved in 
water. Also preferred are scrims coated with other thermosetting resins or 
with thermoplastic resins, such as polyvinyl chloride resins. 
In the bonding process, the scrim and the paper are brought together and 
passed over steam cans. The pressure from tension is sufficient to bond 
the scrim to the paper. It is preferred to bind the scrim to the paper 
first and treat the composite paper and scrim while bonded together. The 
scrim may also be incorporated directly into the paper during paper 
manufacture or placed between two layers of paper. 
The preferred scrim is a continuous multi-filament fiberglass and may have 
a yarn number from 150 to 18 1/0 and may range between 33 and 264 tex. We 
prefer to use ECG 37 1/0, in which 37 indicates a yield of 3,700 yards of 
yarn per one pound. Nylon or polyester, which provides toughness and 
elongation in the facing, may be used. The strength of the preferred scrim 
is 30 to 40 lbs. per inch (5 to 7 kgs per cm.) of width and scrims with 
strengths ranging from 5 to 90 lbs. per inch (1 to 16 kgs per cm.) of 
width may be used. The preferred openings between yarns in the scrim range 
from one-tenth to about one inch (0.25 to 2.5 cm.) between yarns and 
larger so long as sufficient strength for wind resistence or other 
purposes is provided. It is preferred to place the scrim material adjacent 
to the insulation foam during the manufacture of the insulation board. 
Boards having facings of our invention have been subjected to wind uplift 
tests, which are tests used to determine whether a roofing material will 
withstand the force of wind when installed, and the facing of this 
invention has proven sufficiently strong to meet industry standards for 
such strength. 
In the processes of preparing the facing of our invention, paper, whether 
bonded to the scrim previously or not, is treated with a treatment to be 
described below. Preferably the treatment is in liquid form and the paper 
is led through the treatment where it picks up the materials to be added 
to the paper. Thereafter, the paper may be squeezed and dried. Various 
methods of applying the treatment may be used, including dip-coaters, 
doctor blade devices, and the like. 
The preferred method of treating the paper with materials of the treatment 
is to have the lower portion of one roller partially submerged in a trough 
of the treatment material and the paper and scrim composite run against 
the upper portion of the same roller so that an amount of the treatment 
material is transferred to the scrim and paper composite. A second roller 
above the first roller controls the movement of the paper and scrim 
composite and the uniformity of the amount of material on the paper/scrim 
composite. Thereafter the composite is led in a preferred method to steam 
cans to expedite drying. It is preferred to pass the paper over steam cans 
at 300.degree. F. (150 .degree. C.) which drives the water off and 
additionally may cause some flow of the treatment material as in the case 
of polyvinyl chloride. It is believed that such flow tends to further fill 
interstices and reduce porosity in the paper and it may tend also to coat 
further and more uniformly fibers within the paper with the treatment 
materials. It is preferred to use in such additional heat treatment a 
polyvinyl chloride resin which tends to form a film at temperatures 
between about 180.degree. F. and 230.degree. F. (80.degree. C. to 
110.degree. C.). 
The treatment applied to the paper or the paper/scrim combination is 
preferably a mixture or solution comprising a polymer, a fire-retardant, 
and a water-repellant. The polymer and other treatment materials may also 
be added in the form of a dispersion or an emulsion and typically include 
small particles of treatment materials. Since the liquid permeability of 
polyvinyl chloride is less than the liquid permeability of paper fibers, 
the treating of paper fibers with such polymer dispersion reduces the 
liquid permeability of the paper overall, thereby reducing transmission of 
liquids through the paper and bleed-through. In addition, polyvinyl 
chloride or other treatment materials tend to block or reduce the number 
or size of pores in the paper, thus reducing the porosity of the paper and 
also reducing the amount of bleed through. Polyvinyl chloride materials we 
most prefer have a glass transition temperature of about 62.degree. C. 
Also preferred are polyvinyl chloride materials with a glass transition 
temperature of 30.degree. C. to 75.degree. C., and such materials with 
glass transition temperature ranging from about 0.degree. to about 
75.degree. C. may be used. 
Fire retardants may be halogenated paraffin retardants or halogenated 
phosphorous complexes or other such materials, including bromated 
phosphorous complexes, and antimony with a halogenated organic compound. 
Ammonium phosphate, colloidal antimony, borax and and other similar 
materials may also be used. 
Water repellants may preferably be dispersion of paraffin or other high 
molecular weight waxes. A combination of a paraffin dispersion plus a 
quaternized ammonium salt, for example, or emulsions of polyethylene, 
which are essentially high molecular weight paraffins, and other water 
repellants may be used. Water repellancy and fire retardancy may be 
imparted by a single compound or composition which possesses both 
properties, or by a properly selected polymer. 
One advantage of the treatment of the present invention is that the degree 
of porosity may be controlled. Certain amounts of porosity are often 
desirable in the final product in order that (a) vapors may pass through 
the facing, and (b) the foam-forming liquids may flow partially into the 
facing and provide a good bond. However, it is always important that the 
facing be sufficiently low in porosity that low viscosity liquid plastic 
foam-forming materials used in making plastic foamed construction 
insulation board do not bleed through the facing during manufacture. Using 
an air permeability measurement, we determined the porosity of papers 
utilized in the present invention both before treatment and after 
treatment and found that for a 12-lb. paper, the porosity, as measured in 
terms of air permeability, before treatment is 100 cu. ft. per minute per 
sq. ft. of air passing through the paper at one-half inch of water 
pressure ("c.f./m./sq. ft.")(31 cubic meters per minute per square meter). 
After treatment, the same paper has an air permeability of 40 c.f./m./sq. 
ft. which will make a satisfactory but not superior product. In the case 
of untreated 20 lb. paper, the air permeability was measured at 12 
c.f./m./sq. ft. and after treatment was reduced to 7 c.f./m./sq. ft. We 
note in this connection that glass mat of the prior art when treated with 
non-wicking agents may have an air permeability of 650 c.f./m./sq. ft. 
Not only does the treatment of the present invention reduce the porosity of 
the paper, but in preferred embodiments it improves the physical 
properties, including the strength and toughness of the paper. For 
example, untreated 20 pound paper had a tensile strength of 6.7 pounds per 
inch of width (1.2 kg./cm) and a stretch or elongation of 3.0%. A sample 
of the same paper treated in accordance at this invention had a strength 
of 8.3 pounds per inch of width (1.48 kg/cm.) with an elongation of 4.2%. 
Such increases in strength and elongation increase the toughness of the 
paper and provide a facing which is more durable than untreated paper with 
respect to certain stresses, such as holes caused by fingers which can be 
created inadvertantly in shipping or installation. 
The treatment provided by the present invention is to be distinguished from 
mere painting of surfaces which produces a sealed surface and gives the 
foamed plastic no fibers to impregnate partially and bind to solidly. The 
treatment of the present invention is also to be distinguished further 
from the application solely of non-wicking agents such as fluorocarbon 
non-wicking agents, which are applied in substantially smaller weight 
amounts providing essentially only a monomolecular coating, and which 
because of their low surface-free energy create surfaces which make 
virtually all liquids bead-up and roll off, including low viscosity, foam 
forming liquds used in making plastic foam. Such liquids typically contain 
surfactants to make them wet even water-repellant surfaces. Non-wicking 
agents provide substantially less wetable surfaces than are created by the 
water repellants of the present invention. As the term "water repellant" 
is used herein, it does not include "non-wicking" agents. 
The mechanism by which the present invention reduces bleed through is 
believed to lie mainly in two factors, both of which are related to the 
physical blocking of liquid passage through the paper, not to he 
repellancy of liquids by means of non-wicking agents. First, the treatment 
of the present invention reduces the porosity of the paper by blocking 
some or all of the pores. Second, in the present invention the treatment 
may also coat the fibers of the paper and because the treatment has less 
permeability to liquids than the paper fibers, the flow of liquids through 
the fibers of the paper is reduced. The materials of the present invention 
should also be distinguished from asphalt impregnated heavy papers in 
which the asphalt material saturates and totally fills the paper and is 
believed to increase the weight of the composite by more than 100% of the 
weight of the paper. 
The dry weight of the materials in the treatment of this invention may 
range between 10% to 100% of the weight of the paper or preferably may 
range between 10% and 40%. The optimal treatment weight as a percent of 
paper weight is 20% to 35%.

Set forth below are specific examples of the invention in which the dry 
weight of the components of the treatment are set forth as numerical 
ratios. These components are combined with sufficient water to make a 
suitable solution or dispersion. The water is removed in later processing, 
leaving behind the dry components of the treatment. 
EXAMPLE 1 
Treatment Materials: 
______________________________________ 
Wet 
Dry Weight 
Weight 
______________________________________ 
Poly(vinyl chloride) 100 178.6 
(GEON 351, a product 
of B.F. Goodrich) 
Fire retardants 40 120.0 
(FYARESTOR 330, a 
bromated phosphorous 
complex, Pearsall 
Chemicals, a division of 
Witco Chemical) 
(FYARESTOR 100E, a halogenated 
10 10.0 
paraffin, Pearsall Chemicals) 
(HFR 201, a colloaidal 
12.5 25.00 
antimony pentoxide, 
Harshaw Chemical) 
[or a comparable Nyacol 
product may be used] 
Water repellants 10 40.0 
(AEROTEX 96 a blend 
of a parafin and a quaternary 
ammonium salt, American 
Cynamid) 
(Accelerator UTX for 1.5 6.0 
AEROTEX 96) 
(FC-824, a flurochemical 
1.5 3.75 
designed to impart alcohol 
and water repallancy, 3 M Co.) 
Water -- 300.00 
170.5 683.35 
______________________________________ 
A twenty-pound tissue paper with adhesively bonded scrim was treated with 
this treatment and dried. The weight gain was about 26% of the weight of 
the paper. 
EXAMPLE 2 
Treatment Materials: 
______________________________________ 
Dry Weight 
Wet Weight 
______________________________________ 
Poly(vinyl chloride) 
100 178.6 
(GEON 351) 
Fire retardants 
50 150.0 
(FYARESTOR 330) 
(HFR 201) 20 40.0 
Water repellants 
10 40.0 
(AEROTEX 96) 
(Accelerator UTX) 
1.5 6.0 
(FC-824) 1.5 3.75 
Water -- 300.00 
183 718.35 
______________________________________ 
A twenty-pound tissue paper with adhesively bonded scrim was treated with 
this treatment and dried. The weight gain was about 25% of the weight of 
the paper. 
EXAMPLE 3 
A 20 pound bleached tissue paper was treated with an aqueous blend of the 
following: 
______________________________________ 
Component Dry Weight 
______________________________________ 
Poly(vinyl chloride) Latex 
100 
Colloidal Antimony Pentoxide 
20 
Brominated Phosphorous complex 
50 
Reactive water repellant 
10 
Catalyst for water repellant 
2 
______________________________________ 
After drying, the resulting weight gain was in the 20-35% weight range. 
EXAMPLE 4 
The treated tissue in Example 3 was combined with a glass scrim having two 
glass yarns per inch in both directions, each yarn having a breaking 
strength of about 16 pounds. 
EXAMPLE 5 
The treated tissue in Example 3 may be combined with a polyester scrim 
having 2 yarns per inch in both directions, each yarn having a breaking 
strength of about 15 pounds. 
EXAMPLE 6 
The tissue in Examples 3 or 4 may be treated with additional amounts of the 
latex component and the water repellant and catalyst may be eliminated. 
EXAMPLE 7 
A tissue similar to that in Example 3 or 4 may be made except that 35% of 
the weight of the fibers in the paper may be glass. 
EXAMPLE 8 
A urethane or isocyanurate foam board may be made faced on one or both 
sides with facings of the above examples. 
EXAMPLE 9 
The treated tissue in Example 3 may be subsequently rendered less porous by 
application of heat and pressure, e.g., by passing it through hot squeeze 
rolls.